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“Can p-channel tunnel field-effect transistors perform as good as n-channel?”.Verhulst AS, Verreck D, Pourghaderi MA, Van de Put M, Sorée B, Groeseneken G, Collaert N, Thean AV-Y, Applied physics letters 105, 043103 (2014). http://doi.org/10.1063/1.4891348
Abstract: We show that bulk semiconductor materials do not allow perfectly complementary p- and n-channel tunnel field-effect transistors (TFETs), due to the presence of a heavy-hole band. When tunneling in p-TFETs is oriented towards the gate-dielectric, field-induced quantum confinement results in a highest-energy subband which is heavy-hole like. In direct-bandgap IIIV materials, the most promising TFET materials, phonon-assisted tunneling to this subband degrades the subthreshold swing and leads to at least 10x smaller on-current than the desired ballistic on-current. This is demonstrated with quantum-mechanical predictions for p-TFETs with tunneling orthogonal to the gate, made out of InP, In0.53Ga0.47As, InAs, and a modified version of In0.53Ga0.47As with an artificially increased conduction-band density-of-states. We further show that even if the phonon-assisted current would be negligible, the build-up of a heavy-hole-based inversion layer prevents efficient ballistic tunneling, especially at low supply voltages. For p-TFET, a strongly confined n-i-p or n-p-i-p configuration is therefore recommended, as well as a tensily strained line-tunneling configuration. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 8
DOI: 10.1063/1.4891348
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“Role of intrinsic molecular dipole in energy level alignment at organic interfaces”. Lindell L, Çakir D, Brocks G, Fahlman M, Braun S, Applied Physics Letters 102, 223301 (2013). http://doi.org/10.1063/1.4809567
Abstract: The energy level alignment in metal-organic and organic-organic junctions of the widely used materials tris-(8-hydroxyquinoline) aluminum (Alq(3)) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is investigated. The measured alignment schemes for single and bilayer films of Alq(3) and NTCDA are interpreted with the integer charge transfer (ICT) model. Single layer films of Alq(3) feature a constant vacuum level shift of similar to 0.2-0.4 eV in the absence of charge transfer across the interface. This finding is attributed to the intrinsic dipole of the Alq(3) molecule and (partial) ordering of the molecules at the interfaces. The vacuum level shift changes the onset of Fermi level pinning, as it changes the energy needed for equilibrium charge transfer across the interface. (C) 2013 AIP Publishing LLC.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 22
DOI: 10.1063/1.4809567
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“Stress dependence of the suspended graphene work function : vacuum Kelvin probe force microscopy and density functional theory”. Volodin A, Van Haesendonck C, Leenaerts O, Partoens B, Peeters FM, Applied physics letters 110, 193101 (2017). http://doi.org/10.1063/1.4982931
Abstract: We report on work function measurements on graphene, which is exfoliated over a predefined array of wells in silicon oxide, by Kelvin probe force microscopy operating in a vacuum. The obtained graphene sealed microchambers can support large pressure differences, providing controllable stretching of the nearly impermeable graphene membranes. These measurements allow detecting variations of the work function induced by the mechanical stresses in the suspended graphene where the work function varies linearly with the strain and changes by 62 +/- 2 meV for 1 percent of strain. Our related ab initio calculations result in a work function variation that is a factor of 1.4 larger than the experimental value. The limited discrepancy between the theory and the experiment can be accounted for by a charge transfer from the unstrained to the strained graphene regions. Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 8
DOI: 10.1063/1.4982931
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“Graphene membrane as a pressure gauge”. Milovanović, SP, Tadic MZ, Peeters FM, Applied physics letters 111, 043101 (2017). http://doi.org/10.1063/1.4995983
Abstract: Straining graphene results in the appearance of a pseudo-magnetic field which alters its local electronic properties. Applying a pressure difference between the two sides of the membrane causes it to bend/bulge resulting in a resistance change. We find that the resistance changes linearly with pressure for bubbles of small radius while the response becomes non-linear for bubbles that stretch almost to the edges of the sample. This is explained as due to the strong interference of propagating electronic modes inside the bubble. Our calculations show that high gauge factors can be obtained in this way which makes graphene a good candidate for pressure sensing. Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 11
DOI: 10.1063/1.4995983
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“Graphene quantum blisters : a tunable system to confine charge carriers”. Abdullah HM, Van der Donck M, Bahlouli H, Peeters FM, Van Duppen B, Applied physics letters 112, 213101 (2018). http://doi.org/10.1063/1.5023896
Abstract: Due to Klein tunneling, electrostatic confinement of electrons in graphene is not possible. This hinders the use of graphene for quantum dot applications. Only through quasi-bound states with finite lifetime has one achieved to confine charge carriers. Here, we propose that bilayer graphene with a local region of decoupled graphene layers is able to generate bound states under the application of an electrostatic gate. The discrete energy levels in such a quantum blister correspond to localized electron and hole states in the top and bottom layers. We find that this layer localization and the energy spectrum itself are tunable by a global electrostatic gate and that the latter also coincides with the electronic modes in a graphene disk. Curiously, states with energy close to the continuum exist primarily in the classically forbidden region outside the domain defining the blister. The results are robust against variations in size and shape of the blister which shows that it is a versatile system to achieve tunable electrostatic confinement in graphene. Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 9
DOI: 10.1063/1.5023896
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“Topological Dirac semimetal phase in <tex>, $GexSny alloys”. Kong X, Li L, Peeters FM, Applied physics letters 112, 251601 (2018). http://doi.org/10.1063/1.5037121
Abstract: Recently, two stable allotropes (germancite and stancite) for the group IV elements (Ge and Sn) with a staggered layered dumbell structure were proposed to be three-dimensional (3D) topological Dirac semimetals [Phys. Rev. B 93, 241117 (2016)]. A pair of Dirac points is on the rotation axis away from the time-reversal invariant momentum, and the stability of the 3D bulk Dirac points is protected by the C-3 rotation symmetry. Here, we use the first principles calculations to investigate GexSny alloys which share the same rhombohedral crystal structure with the space group of D-3d(6). Six GexSny alloys are predicted to be energetically and dynamically stable, where (x, y) = (8, 6) and (6, 8) and the alpha and beta phases of (10, 4) and (4, 10). Our results demonstrate that all the six GexSny alloys are topological Dirac semimetals. The different nontrivial surface states and surface Fermi arcs are identified. Our work will substantially enrich the family of 3D Dirac semimetals which are within the reach of experimental realization. Published by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 8
DOI: 10.1063/1.5037121
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“Strain engineered linear dichroism and Faraday rotation in few-layer phosphorene”. Li LL, Peeters FM, Applied physics letters 114, 243102 (2019). http://doi.org/10.1063/1.5103172
Abstract: We investigate theoretically the linear dichroism and the Faraday rotation of strained few-layer phosphorene, where strain is applied uniaxially along the armchair or zigzag direction of the phosphorene lattice. We calculate the optical conductivity tensor of uniaxially strained few-layer phosphorene by means of the Kubo formula within the tight-binding approach. We show that the linear dichroism and the Faraday rotation of few-layer phosphorene can be significantly modulated by the applied strain. The modulation depends strongly on both the magnitude and direction of strain and becomes more pronounced with increasing number of phosphorene layers. Our results are relevant for mechano-optoelectronic applications based on optical absorption and Hall effects in strained few-layer phosphorene.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 12
DOI: 10.1063/1.5103172
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“Coulomb drag in strongly coupled quantum wells : temperature dependence of the many-body correlations”. Zarenia M, Conti S, Peeters FM, Neilson D, Applied physics letters 115, 202105 (2019). http://doi.org/10.1063/1.5116803
Abstract: We investigate the effect of the temperature dependence of many-body correlations on hole-hole Coulomb drag in strongly coupled GaAs/GaAlAs double quantum wells. For arbitrary temperatures, we obtained the correlations using the classical-map hypernetted-chain approach. We compare the temperature dependence of the resulting drag resistivities rho D(T) at different densities with rho D(T) calculated assuming correlations fixed at zero temperature. Comparing the results with those when correlations are completely neglected, we confirm that correlations significantly increase the drag. We find that the drag becomes sensitive to the temperature dependence of T greater than or similar to 2TF, twice the Fermi temperature. Our results show excellent agreement with available experimental data. Published under license by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 2
DOI: 10.1063/1.5116803
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“2D ferromagnetism at finite temperatures under quantum scrutiny”. Vanherck J, Bacaksiz C, Sorée B, Milošević, MV, Magnus W, Applied Physics Letters 117, 052401 (2020). http://doi.org/10.1063/5.0015619
Abstract: Recent years have seen a tremendous rise of two-dimensional (2D) magnetic materials, several of which were verified experimentally. However, most of the theoretical predictions to date rely on ab initio methods, at zero temperature and fluctuation-free, while one certainly expects detrimental quantum fluctuations at finite temperatures. Here, we present the solution of the quantum Heisenberg model for honeycomb/hexagonal lattices with anisotropic exchange interaction up to third nearest neighbors and in an applied field in arbitrary direction, which answers the question whether long-range magnetization can indeed survive in the ultrathin limit of materials, up to which temperature, and what the characteristic excitation (magnon) frequencies are, all essential to envisaged applications of magnetic 2D materials. We find that long-range magnetic order persists at finite temperature for materials with overall easy-axis anisotropy. We validate the calculations on the examples of monolayers CrI3, CrBr3, and MnSe2. Moreover, we provide an easy-to-use tool to calculate Curie temperatures of new 2D computational materials.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4
Times cited: 8
DOI: 10.1063/5.0015619
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“Monolayer 1T-LaN₂, : Dirac spin-gapless semiconductor of p-state and Chern insulator with a high Chern number”. Li L, Kong X, Chen X, Li J, Sanyal B, Peeters FM, Applied Physics Letters 117, 143101 (2020). http://doi.org/10.1063/5.0023531
Abstract: Two-dimensional transition-metal dinitrides have attracted considerable attention in recent years due to their rich magnetic properties. Here, we focus on rare-earth-metal elements and propose a monolayer of lanthanum dinitride with a 1T structural phase, 1T-LaN2. Using first-principles calculations, we systematically investigated the structure, stability, magnetism, and band structure of this material. It is a flexible and stable monolayer exhibiting a low lattice thermal conductivity, which is promising for future thermoelectric devices. The monolayer shows the ferromagnetic ground state with a spin-polarized band structure. Two linear spin-polarized bands cross at the Fermi level forming a Dirac point, which is formed by the p atomic orbitals of the N atoms, indicating that monolayer 1T-LaN2 is a Dirac spin-gapless semiconductor of p-state. When the spin-orbit coupling is taken into account, a large nontrivial indirect bandgap (86/354meV) can be opened at the Dirac point, and three chiral edge states are obtained, corresponding to a high Chern number of C=3, implying that monolayer 1T-LaN2 is a Chern insulator. Importantly, this kind of band structure is expected to occur in more monolayers of rare-earth-metal dinitride with a 1T structural phase.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4
Times cited: 19
DOI: 10.1063/5.0023531
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“Substrate dependent terahertz response of monolayer WS₂”. Dong HM, Tao ZH, Li LL, Huang F, Xu W, Peeters FM, Applied Physics Letters 116, 1 (2020). http://doi.org/10.1063/5.0006617
Abstract: We investigate experimentally the terahertz (THz) optoelectronic properties of monolayer (ML) tungsten disulfide (WS2) placed on different substrates using THz time-domain spectroscopy (TDS). We find that the THz optical response of n-type ML WS2 depends sensitively on the choice of the substrate. This dependence is found to be a consequence of substrate induced charge transfer, extra scattering centers, and electronic localization. Through fitting the experimental results with the Drude-Smith formula, we can determine the key sample parameters (e.g., the electronic relaxation time, electron density, and electronic localization factor) of ML WS2 on different substrates. The temperature dependence of these parameters is examined. Our results show that the THz TDS technique is an efficient non-contact method that can be utilized to characterize and investigate the optoelectronic properties of nano-devices based on ML WS2.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4
Times cited: 17
DOI: 10.1063/5.0006617
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“The magnetic, electronic, and light-induced topological properties in two-dimensional hexagonal FeX₂, (X=Cl, Br, I) monolayers”. Kong X, Li L, Liang L, Peeters FM, Liu X-J, Applied Physics Letters 116, 192404 (2020). http://doi.org/10.1063/5.0006446
Abstract: Using Floquet-Bloch theory, we propose to realize chiral topological phases in two-dimensional (2D) hexagonal FeX2 (X=Cl, Br, I) monolayers under irradiation of circularly polarized light. Such 2D FeX2 monolayers are predicted to be dynamically stable and exhibit both ferromagnetic and semiconducting properties. To capture the full topological physics of the magnetic semiconductor under periodic driving, we adopt ab initio Wannier-based tight-binding methods for the Floquet-Bloch bands, with the light-induced bandgap closings and openings being obtained as the light field strength increases. The calculations of slabs with open boundaries show the existence of chiral edge states. Interestingly, the topological transitions with branches of chiral edge states changing from zero to one and from one to two by tuning the light amplitude are obtained, showing that the topological Floquet phase of high Chern number can be induced in the present Floquet-Bloch systems. Published under license by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4
Times cited: 18
DOI: 10.1063/5.0006446
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“A Dirac-semimetal two-dimensional BeN4 : thickness-dependent electronic and optical properties”. Bafekry A, Stampfl C, Faraji M, Yagmurcukardes M, Fadlallah MM, Jappor HR, Ghergherehchi M, Feghhi SAH, Applied Physics Letters 118, 203103 (2021). http://doi.org/10.1063/5.0051878
Abstract: Motivated by the recent experimental realization of a two-dimensional (2D) BeN4 monolayer, in this study we investigate the structural, dynamical, electronic, and optical properties of a monolayer and few-layer BeN4 using first-principles calculations. The calculated phonon band dispersion reveals the dynamical stability of a free-standing BeN4 layer, while the cohesive energy indicates the energetic feasibility of the material. Electronic band dispersions show that monolayer BeN4 is a semi-metal whose conduction and valence bands touch each other at the Sigma point. Our results reveal that increasing the layer number from single to six-layers tunes the electronic nature of BeN4. While monolayer and bilayer structures display a semi-metallic behavior, structures thicker than that of three-layers exhibit a metallic nature. Moreover, the optical parameters calculated for monolayer and bilayer structures reveal that the bilayer can absorb visible light in the ultraviolet and visible regions better than the monolayer structure. Our study investigates the electronic properties of Dirac-semimetal BeN4 that can be an important candidate for applications in nanoelectronic and optoelectronic. Published under an exclusive license by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
DOI: 10.1063/5.0051878
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“Electronic and magnetic properties of two-dimensional of FeX (X = S, Se, Te) monolayers crystallize in the orthorhombic structures”. Bafekry A, Sarsari IA, Faraji M, Fadlallah MM, Jappor HR, Karbasizadeh S, Nguyen V, Ghergherehchi M, Applied Physics Letters 118, 143102 (2021). http://doi.org/10.1063/5.0046721
Abstract: In this Letter, we explore the lattice, dynamical stability, and electronic and magnetic properties of FeTe bulk and FeX (X=S, Se, Te) monolayers using the density functional calculations. The phonon dispersion relation, elastic stability criteria, and cohesive energy results show the stability of studied FeX monolayers. The mechanical properties reveal that all FeX monolayers have a brittle nature. Furthermore, these structures are stable as we move down the 6A group in the periodic table, i.e., from S, Se, and Te. The stability and work function decrease as the electronegativity decreases. The spin-polarized electronic structures demonstrate that the FeTe monolayer has a total magnetization of 3.8 mu (B), which is smaller than the magnetization of FeTe bulk (4.7 mu (B)). However, FeSe and FeS are nonmagnetic monolayers. The FeTe monolayer can be a good candidate material for spin filter applications due to its electronic and magnetic properties. This study highlights the bright prospect for the application of FeX monolayers in electronic structures.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
DOI: 10.1063/5.0046721
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“Two-dimensional semimetal states in transition metal trichlorides : a first-principles study”. Yu Y, Xie X, Liu X, Li J, Peeters FM, Li L, Applied physics letters 121, 112405 (2022). http://doi.org/10.1063/5.0105605
Abstract: The two-dimensional (2D) transition metal trihalide (TMX3, X = Cl, Br, I) family has attracted considerable attention in recent years due to the realization of CrCl3, CrBr3, and CrI3 monolayers. Up to now, the main focus of the theoretically predicted TMX3 monolayers has been on the Chern insulator states, which can realize the quantum anomalous Hall effect. Here, using first-principles calculations, we theoretically demonstrate that the stable OsCl3 monolayer has a ferromagnetic ground state and a spin-polarized Dirac point without spin-orbit coupling (SOC), which disappears in the band structure of a Janus OsBr1.5Cl1.5 monolayer. We find that OsCl3 exhibits in-plane magnetization when SOC is included. By manipulating the magnetization direction along the C-2 symmetry axis of the OsCl3 structure, a gapless half-Dirac semimetal state with SOC can be achieved, which is different from the gapped Chern insulator state. Both semimetal states of OsCl3 monolayer without and with SOC exhibit a linear half-Dirac point (twofold degenerate) with high Fermi velocities. The achievement of the 2D semimetal state with SOC is expected to be found in other TMX3 monolayers, and we confirm it in a TiCl3 monolayer. This provides a different perspective to study the band structure with SOC of the 2D TMX3 family.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4
Times cited: 4
DOI: 10.1063/5.0105605
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“Statistical method for thickness measurement of amorphous objects”. van Dyck D, Croitoru MD, Applied physics letters 90, 241911 (2007). http://doi.org/10.1063/1.2749184
Abstract: The authors propose a nondestructive method for the determination of the thickness of an amorphous sample. This method is based on the statistics of the phase of the electron exit wave function, which depend on the number of atoms traversed by the incident electron which itself is a function of the thickness of the object. The accuracy of this method has been checked numerically by the multislice method and compared with that based on the mean inner potential. (c) 2007 American Institute of Physics.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 3.411
Times cited: 4
DOI: 10.1063/1.2749184
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“Hybrid ferromagnetic/semiconductor Hall effect device”. Reijniers J, Peeters FM, Applied physics letters 73, 357 (1998). http://doi.org/10.1063/1.121833
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Engineering Management (ENM)
Impact Factor: 3.411
Times cited: 35
DOI: 10.1063/1.121833
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“Ab initio computation of the mean inner Coulomb potential of amorphous carbon structures”. Schowalter M, Titantah JT, Lamoen D, Kruse P, Applied physics letters 86, 112102 (2005). http://doi.org/10.1063/1.1885171
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 15
DOI: 10.1063/1.1885171
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“Atomic layer epitaxy of Ruddlesden-Popper SrO(SrTiO3)n films by means of metalorganic aerosol deposition”. Jungbauer M, Huehn S, Egoavil R, Tan H, Verbeeck J, Van Tendeloo G, Moshnyaga V, Applied physics letters 105, 251603 (2014). http://doi.org/10.1063/1.4905055
Abstract: We report an atomic layer epitaxial growth of Ruddlesden-Popper (RP) thin films of SrO(SrTiO3)(n) (n = infinity, 2, 3, 4) by means of metalorganic aerosol deposition (MAD). The films are grown on SrTiO3(001) substrates by means of a sequential deposition of Sr-O/Ti-O-2 atomic monolayers, monitored in-situ by optical ellipsometry. X-ray diffraction and transmission electron microscopy (TEM) reveal the RP structure with n = 2-4 in accordance with the growth recipe. RP defects, observed by TEM in a good correlation with the in-situ ellipsometry, mainly result from the excess of SrO. Being maximal at the film/substrate interface, the SrO excess rapidly decreases and saturates after 5-6 repetitions of the SrO(SrTiO3)(4) block at the level of 2.4%. This identifies the SrTiO3 substrate surface as a source of RP defects under oxidizing conditions within MAD. Advantages and limitations of MAD as a solution-based and vacuum-free chemical deposition route were discussed in comparison with molecular beam epitaxy. (C) 2014 AIP Publishing LLC.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 32
DOI: 10.1063/1.4905055
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“Atomic scale electron vortices for nanoresearch”. Verbeeck J, Schattschneider P, Lazar S, Stöger-Pollach M, Löffler S, Steiger-Thirsfeld A, Van Tendeloo G, Applied physics letters 99, 203109 (2011). http://doi.org/10.1063/1.3662012
Abstract: Electron vortex beams were only recently discovered and their potential as a probe for magnetism in materials was shown. Here we demonstrate a method to produce electron vortex beams with a diameter of less than 1.2 Å. This unique way to prepare free electrons to a state resembling atomic orbitals is fascinating from a fundamental physics point of view and opens the road for magnetic mapping with atomic resolution in an electron microscope.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 90
DOI: 10.1063/1.3662012
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“Atomic scale investigation of a PbTiO3/SrRuO3/DyScO3 heterostructure”. Egoavil R, Tan H, Verbeeck J, Bals S, Smith B, Kuiper B, Rijnders G, Koster G, Van Tendeloo G, Applied physics letters 102, 223106 (2013). http://doi.org/10.1063/1.4809597
Abstract: An epitaxial PbTiO3 thin film grown on self-organized crystalline SrRuO3 nanowires deposited on a DyScO3 substrate with ordered DyO and ScO2 chemical terminations is investigated by transmission electron microscopy. In this PbTiO3/SrRuO3/DyScO3 heterostructure, the SrRuO3 nanowires are assumed to grow on only one type of substrate termination. Here, we report on the structure, morphology, and chemical composition analysis of this heterostructure. Electron energy loss spectroscopy reveals the exact termination sequence in this complex structure. The energy loss near-edge structure of the Ti-L-2,L-3, Sc-L-2,L-3, and O K edges shows intrinsic interfacial electronic reconstruction. Furthermore, PbTiO3 domain walls are observed to start at the end of the nanowires resulting in atomic steps on the film surface. (C) 2013 AIP Publishing LLC.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 12
DOI: 10.1063/1.4809597
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“Convergent beam electron-diffraction investigation of lattice mismatch and static disorder in GaAs/GaAs1-xNx intercalated GaAs/GaAs1-xNx:H heterostructures”. Frabboni S, Grillo V, Gazzadi GC, Balboni R, Trotta R, Polimeni A, Capizzi M, Martelli F, Rubini S, Guzzinati G, Glas F;, Applied physics letters 101, 111912 (2012). http://doi.org/10.1063/1.4752464
Abstract: Hydrogen incorporation in diluted nitride semiconductors dramatically modifies the electronic and structural properties of the crystal through the creation of nitrogen-hydrogen complexes. We report a convergent beam electron-diffraction characterization of diluted nitride semiconductor-heterostructures patterned at a sub-micron scale and selectively exposed to hydrogen. We present a method to determine separately perpendicular mismatch and static disorder in pristine and hydrogenated heterostructures. The roles of chemical composition and strain on static disorder have been separately assessed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752464]
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 1
DOI: 10.1063/1.4752464
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“Critical size for exchange bias in ferromagnetic-antiferromagnetic particles”. Dobrynin AN, Ievlev DN, Temst K, Lievens P, Margueritat J, Gonzalo J, Afonso CN, Zhou SQ, Vantomme A, Piscopiello E, Van Tendeloo G, Applied physics letters 87, 012501 (2005). http://doi.org/10.1063/1.1978977
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 92
DOI: 10.1063/1.1978977
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“Direct evidence of spontaneous quantum dot formation in a thick InGaN epilayer”. Nistor L, Bender H, Vantomme A, Wu MF, van Landuyt J, O'Donnell KP, Martin R, Jacobs K, Moerman I, Applied physics letters 77, 507 (2000). http://doi.org/10.1063/1.127026
Abstract: We report a direct observation of quantum dots formed spontaneously in a thick InGaN epilayer by high resolution transmission electron microscopy. Investigation of a (280 nm thick) In0.22Ga0.78N single layer, emitting in the blue/green spectral region, reveals quantum dots with estimated sizes in the range of 1.5-3 nm. Such sizes are in very good agreement with calculations based on the luminescence spectra of this specimen. (C) 2000 American Institute of Physics. [S0003-6951(00)00930-X].
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 44
DOI: 10.1063/1.127026
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“Direct visualization of boron dopant distribution and coordination in individual chemical vapor deposition nanocrystalline B-doped diamond grains”. Lu Y-G, Turner S, Verbeeck J, Janssens SD, Wagner P, Haenen K, Van Tendeloo G, Applied physics letters 101, 041907 (2012). http://doi.org/10.1063/1.4738885
Abstract: The boron dopant distribution in individual heavily boron-doped nanocrystalline diamond film grains, with sizes ranging from 100 to 350nm in diameter, has been studied using a combination of high resolution annular dark field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy. Using these tools, the boron distribution and local boron coordination have been determined. Quantification results reveal embedding of B dopants in the diamond lattice, and a preferential enrichment of boron at defective areas and twin boundaries. Coordination mapping reveals a distinct difference in coordination of the B dopants in “pristine” diamond areas and in defective regions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4738885]
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 59
DOI: 10.1063/1.4738885
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“Doping of interfaces in (La0.7Sr0.3MnO3)1-x:(MgO)x composite films”. Köster S, Moshnyaga V, Samwer K, Lebedev OI, Van Tendeloo G, Shapoval O, Belenchuk A, Applied physics letters 81, 1648 (2002). http://doi.org/10.1063/1.1503849
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 35
DOI: 10.1063/1.1503849
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“Electrical switching in Fe/Cr/MgO/Fe magnetic tunnel junctions”. Halley D, Majjad H, Bowen M, Najjari N, Henry Y, Ulhaq-Bouillet C, Weber W, Bertoni G, Verbeeck J, Van Tendeloo G, Applied physics letters 92, 212115 (2008). http://doi.org/10.1063/1.2938696
Abstract: Hysteretic resistance switching is observed in epitaxial Fe/Cr/MgO/Fe magnetic tunnel junctions under bias voltage cycling between negative and positive values of about 1 V. The junctions switch back and forth between high- and low-resistance states, both of which depend on the device bias history. A linear dependence is found between the magnitude of the tunnel magnetoresistance and the crafted resistance of the junctions. To explain these results, a model is proposed that considers electron transport both by elastic tunneling and by defect-assisted transmission. (c) 2008 American Institute of Physics.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 33
DOI: 10.1063/1.2938696
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“Electron energy-loss spectroscopy study of a (LaMnO3)8(SrMnO3)4 heterostructure”. Verbeeck J, Lebedev OI, Van Tendeloo G, Silcox J, Mercey B, Hervieu M, Haghiri-Gosnet AM, Applied physics letters 79, 2037 (2001). http://doi.org/10.1063/1.1403316
Abstract: An epitaxially grown heterostructure consisting of alternating layers of LaMnO3 (8 unit cells) and SrMnO3 (4 unit cells) on a SrTiO3 substrate has been studied by a combination of electron energy-loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM) on an atomic scale. Excitation edges of all elements are captured with subnanometer spatial accuracy, and parametrized to obtain chemical profiles. The fine-edge structure of O K and Mn L-2,L-3 edges are interpreted as signatures of the local electronic structure and show a spatial modulation of the concentration of holes with O 2p character. The chemical concentration is found to be different for the bottom and top interface of a SrMnO3 layer. HRTEM complements the EELS results and confirms the asymmetry of the interfaces. (C) 2001 American Institute of Physics.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 19
DOI: 10.1063/1.1403316
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“Epitaxial strain induced metal insulator transition in La0.9Sr0.1MnO3 and La0.88Sr0.1MnO3 thin films”. Razavi FS, Gross G, Habermeier H-U, Lebedev O, Amelinckx S, Van Tendeloo G, Vigliante A, Applied physics letters 76, 155 (2000). http://doi.org/10.1063/1.125687
Abstract: We are reporting an unexpected metal insulator transition at the ferromagnetic phase-transition temperature for thin films of La0.9Sr0.1MnO3 (< 50 nm), grown on a (100) face of SrTiO3 substrate. For the thicker films (> 50 nm), similar to the single crystal, no such transition is observed below T-C. Additionally, we observe the suppression of the features associated with charge or orbital ordering in intentionally La-deficient thin films of La0.88Sr0.1MnO3 (< 75 nm). In thin films, transmission electron microscopy reveals a compressive strain due to the epitaxial growth, that is, lattice parameters adopt those of the cubic lattice of SrTiO3. As the film thickness increases, coherent microtwinning is observed in the films and the films relax to a orthorhombic structure. (C) 2000 American Institute of Physics. [S0003-6951(00)00402-2].
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 91
DOI: 10.1063/1.125687
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“Flowerlike ZnO nanocones and nanowires: preparation, structure, and luminescence”. Du GH, Xu F, Yuan ZY, Van Tendeloo G, Applied physics letters 88, 243101 (2006). http://doi.org/10.1063/1.2211007
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.411
Times cited: 76
DOI: 10.1063/1.2211007
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