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“Interpretation of electron diffraction from carbon nanotube bundles presenting precise helicity”. Colomer J-F, Henrard L, Launois P, Van Tendeloo G, Lucas AA, Lambin P, Physical review : B : condensed matter and materials physics 70, 075408 (2004). http://doi.org/10.1103/PhysRevB.70.075408
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 19
DOI: 10.1103/PhysRevB.70.075408
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“Interpretation of TOF-SIMS depth profiles from ultrashallow high-k dielectric stacks assisted by hybrid collisional computer simulation”. Ignatova VA, Möller W, Conard T, Vandervorst W, Gijbels R, Applied physics A : materials science &, processing 81, 71 (2005). http://doi.org/10.1007/s00339-005-3239-8
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.455
Times cited: 4
DOI: 10.1007/s00339-005-3239-8
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“Intersubband plasmons in quasi-one-dimensional electron systems on a liquid helium surface”. Tavares MRS, Hai G-Q, Peeters FM, Studart N, Physical review : B : condensed matter and materials physics 68, 140504 (2003). http://doi.org/10.1103/PhysRevB.68.140504
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.68.140504
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“Intersublevel absorption in stacked n-type doped self-assembled quantum dots”. Veljkovic D, Tadić, M, Peeters FM, Materials science forum 494, 37 (2005)
Abstract: The intersublevel absorption in n-doped InAs/GaAs self-assembled quantum-dot molecules composed of three quantum dots is theoretically considered. The transition matrix elements and the transition energies are found to vary considerably with the spacer thickness. For s polarized light, decreasing the thickness of the spacer between the dots brings about crossings between the transition matrix elements, but the overall absorption is not affected by the variation of the spacer thickness. For p-polarized light and thick spacers, there are no available transitions in the single quantum dot, but a few of them emerge as a result of the electron state splitting in the stacks of coupled quantum dots, which leads to a considerable increase of the transition matrix elements, exceeding by an order of magnitude values of the matrix elements for s-polarized light.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Intersublevel magnetoabsorption in the valence band of p-type InAs/GaAs and Ge/Si self-assembled quantum dots”. Tadić, M, Peeters FM, Physical review : B : condensed matter and materials physics 71, 125342 (2005). http://doi.org/10.1103/PhysRevB.71.125342
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PhysRevB.71.125342
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“Intrinsic optical anisotropy of [001]-grown short-period InAs/GaSb superlattices”. Li LL, Xu W, Peeters FM, Physical review : B : condensed matter and materials physics 82, 235422 (2010). http://doi.org/10.1103/PhysRevB.82.235422
Abstract: We theoretically investigate the intrinsic optical anisotropy or polarization induced by the microscopic interface asymmetry (MIA) in no-common-atom (NCA) InAs/GaSb superlattices (SLs) grown along the [001] direction. The eight-band K⋅P model is used to calculate the electronic band structures and incorporates the MIA effect. A Boltzmann equation approach is employed to calculate the optical properties. We found that in NCA InAs/GaSb SLs, the MIA effect causes a large in-plane optical anisotropy for linearly polarized light and the largest anisotropy occurs for light polarized along the [110] and [11̅ 0] directions. The relative difference between the optical-absorption coefficient for [110]-polarized light and that for [11̅ 0]-polarized light is found to be larger than 50%. The dependence of the in-plane optical anisotropy on temperature, photoexcited carrier density, and layer width is examined in detail. This study is important for optical devices which require the polarization control and selectivity.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 18
DOI: 10.1103/PhysRevB.82.235422
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“Inverse flux quantum periodicity of magnetoresistance oscillations in two-dimensional short-period surface superlattices”. Wang XF, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 69, 035331 (2004). http://doi.org/10.1103/PhysRevB.69.035331
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.69.035331
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“Investigation of the morphology of the mesoporous SBA-16 and SBA-15 materials”. Stevens WJJ, Lebeau K, Mertens M, Van Tendeloo G, Cool P, Vansant EF, The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical 110, 9183 (2006). http://doi.org/10.1021/jp0548725
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT)
Impact Factor: 3.177
Times cited: 109
DOI: 10.1021/jp0548725
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“Ion beam synthesis of Te and Bi nanoclusters in silicon: the effect of post-implantation high frequency electromagnetic field”. Kalitzova M, Peeva A, Ignatova V, Lebedev OI, Zollo G, Vitali G, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms 242, 209 (2006). http://doi.org/10.1016/j.nimb.2005.08.017
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.109
Times cited: 1
DOI: 10.1016/j.nimb.2005.08.017
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“Ion beam synthesis of \beta-SiC at 950 degrees C and structural characterization”. Frangis N, Nejim A, Hemment PLF, Stoemenos J, van Landuyt J, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 –, Symposium J on Correlated Effects in Atomic and Cluster Ion Bombardment and Implantation/Symposium C on Pushing the Limits of Ion Beam, Processing –, Fr 112, 325 (1996). http://doi.org/10.1016/0168-583X(95)01236-2
Abstract: The structure of beta-SiC formed by carbon implantation into Si at high temperatures (850-950 degrees C) at doses ranging between 0.2 X 10(18) to 1 X 10(18) cm(-2) at 200 keV, was studied by combined cross section and high resolution transmission electron microscopy (XTEM and HRTEM). Implantation was performed on (001) and (111) Si wafers. In both cases a buried beta-SiC layer was formed having the same orientation as the Si matrix.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 1.124
Times cited: 9
DOI: 10.1016/0168-583X(95)01236-2
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“Iron catalysts for the growth of carbon nanofibers : Fe, Fe3C or both?”.He Z, Maurice J-L, Gohier A, Lee CS, Pribat D, Cojocaru CS, Chemistry of materials 23, 5379 (2011). http://doi.org/10.1021/cm202315j
Abstract: Iron is a widely used catalyst for the growth of carbon nanotubes (CNTs) or carbon nanofibers (CNFs) by catalytic chemical vapor deposition. However, both Fe and FeC compounds (generally, Fe3C) have been found to catalyze the growth of CNTs/CNFs, and a comparison study of their respective catalytic activities is still missing. Furthermore, the control of the crystal structure of iron-based catalysts, that is α-Fe or Fe3C, is still a challenge, which not only obscures our understanding of the growth mechanisms of CNTs/CNFs, but also complicates subsequent procedures, such as the removal of catalysts for better industrial applications. Here, we show a partial control of the phase of iron catalysts (α-Fe or Fe3C), obtained by varying the growth temperatures during the synthesis of carbon-based nanofibers/nanotubes in a plasma-enhanced chemical vapor deposition reactor. We also show that the structure of CNFs originating from Fe3C is bamboo-type, while that of CNFs originating from Fe is not. Moreover, we directly compare the growth rates of carbon-based nanofibers/nanotubes during the same experiments and find that CNFs/CNTs grown by α-Fe nanoparticles are longer than CNFs grown from Fe3C nanoparticles. The influence of the type of catalyst on the growth of CNFs is analyzed and the corresponding possible growth mechanisms, based on the different phases of the catalysts, are discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 91
DOI: 10.1021/cm202315j
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“KCN chemical etch for interface engineering in Cu2ZnSnSe4 solar cells”. Buffière M, Brammertz G, Sahayaraj S, Batuk M, Khelifi S, Mangin D, El Mel AA, Arzel L, Hadermann J, Meuris M, Poortmans J;, ACS applied materials and interfaces 7, 14690 (2015). http://doi.org/10.1021/acsami.5b02122
Abstract: The removal of secondary phases from the surface of the kesterite crystals is one of the major challenges to improve the performances of Cu2ZnSn(S,Se)(4) (CZTSSe) thin film solar cells. In this Contribution, the KCN/KOH Chemical etching approach, originally developed for the removal of CuxSe phases in Cu(In,Ga)(S,Se)(2) thin films) is applied to CZTSe absorbers exhibiting various chemical compositions. Two distinct electrical behaviors were observed on CZTSe/CdS solar cells after treatment: (i) the improvement of the fill factor (FF) after 30 s of etching for the CZTSe absorbers showing initially a distortion of the electrical characteristic; (ii) the progressive degradation Of the FF after long treatment time for all Cu-poor CZTSe solar cell samples. The first effect can be attributed to the action of KCN on the absorber, that is found to clean the absorber free surface from most of the secondary phases surrounding the kesterite grains (e.g., Se-0, CuxSe, SnSex, SnO2, Cu2SnSe3 phases, excepting the ZnSe-based phases). The second observation was identified as a consequence of the preferential etching of Se, Sn, and Zn from the CZTSe surface by the KOH solution, combined with the modification of the alkali content of the absorber. The formation of a Cu-rich shell at the absorber/buffer layer interface, leading to the increase of the recombination rate at the interface, and the increase in the doping of the absorber layer after etching are found to be at the origin of the deterioration of the FF of the solar cells.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.504
Times cited: 34
DOI: 10.1021/acsami.5b02122
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“Kinetics of energy selective Cs encapsulation in single-walled carbon nanotubes for damage-free and position-selective doping”. Kato T, Neyts EC, Abiko Y, Akama T, Hatakeyama R, Kaneko T, The journal of physical chemistry: C : nanomaterials and interfaces 119, 11903 (2015). http://doi.org/10.1021/acs.jpcc.5b00300
Abstract: A method has been developed for damage-free cesium (Cs) encapsulation within single-walled carbon nanotubes (SWNTs) with fine position selectivity. Precise energy tuning of Cs-ion irradiation revealed that there is a clear energy window (2060 eV) for the efficient encapsulation of Cs through the hexagonal network of SWNT sidewalls without causing significant damage. This minimum energy threshold of Cs-ion encapsulation (∼20 eV) matches well with the value obtained by ab initio simulation (∼22 eV). Furthermore, position-selective Cs encapsulation was carried out, resulting in the successful formation of pn-junction SWNT thin films with excellent environmental stability.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 3
DOI: 10.1021/acs.jpcc.5b00300
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“Kink-antikink vortex transfer in periodic-plus-random pinning potential : theoretical analysis and numerical experiments”. Pogosov WV, Zhao HJ, Misko VR, Peeters FM, Physical review : B : condensed matter and materials physics 81 (2010). http://doi.org/10.1103/PhysRevB.81.024513
Abstract: The influence of random pinning on the vortex dynamics in a periodic square potential under an external drive is investigated. Using numerical experiments and theoretical approach, we found several dynamical regimes of vortex motion that are different from the ones for a regular pinning potential. Vortex transfer is controlled by kinks and antikinks, which either pre-exist in the system or appear spontaneously in pairs and then propagate. When kinks and antikinks collide, they annihilate. We provide clear physical interpretations of the observed features.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.81.024513
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“Kronig-Penney model on bilayer graphene : spectrum and transmission periodic in the strength of the barriers”. Barbier M, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 82, 235408 (2010). http://doi.org/10.1103/PhysRevB.82.235408
Abstract: We show that the transmission through single and double δ-function potential barriers of strength P=VWb/ℏvF in bilayer graphene is periodic in P with period π. For a certain range of P values we find states that are bound to the potential barrier and that run along the potential barrier. Similar periodic behavior is found for the conductance. The spectrum of a periodic succession of δ-function barriers (Kronig-Penney model) in bilayer graphene is periodic in P with period 2π. For P smaller than a critical value Pc, the spectrum exhibits two Dirac points while for P larger than Pc an energy gap opens. These results are extended to the case of a superlattice of δ-function barriers with P alternating in sign between successive barriers; the corresponding spectrum is periodic in P with period π.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 34
DOI: 10.1103/PhysRevB.82.235408
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“Landau-level broadening due to electron-impurity interaction in graphene in strong magnetic fields”. Yang CH, Peeters FM, Xu W, Physical review : B : condensed matter and materials physics 82, 075401:1 (2010). http://doi.org/10.1103/PhysRevB.82.075401
Abstract: The effect of electron-impurity and electron-electron interactions on the energy spectrum of electrons moving in graphene is investigated in the presence of a high magnetic field. We find that the width of the broadened Landau levels exhibits an approximate 1/B dependence near half filling for charged impurity scattering. The Landau-level width, the density of states, and the Fermi energy exhibit an oscillatory behavior as a function of magnetic field. Comparison with experiment shows that scattering with charged impurities cannot be the main scattering mechanism that determines the width of the Landau levels.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.82.075401
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“Landau levels and oscillator strength in a biased bilayer of graphene”. Milton Pereira J, Peeters FM, Vasilopoulos P, Physical review : B : condensed matter and materials physics 76, 115419 (2007). http://doi.org/10.1103/PhysRevB.76.115419
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 91
DOI: 10.1103/PhysRevB.76.115419
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“Landau levels in asymmetric graphene trilayer”. Sena SHR, Pereira JM, Peeters FM, Farias GA, Physical review : B : condensed matter and materials physics 84, 205448 (2011). http://doi.org/10.1103/PhysRevB.84.205448
Abstract: The electronic spectrum of three coupled graphene layers (graphene trilayers) is investigated in the presence of an external magnetic field. We obtain analytical expressions for the Landau level spectrum for both the ABA and ABC type of stacking, which exhibit very different dependence on the magnetic field. We show that layer asymmetry and an external gate voltage can strongly influence the properties of the system.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 30
DOI: 10.1103/PhysRevB.84.205448
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“Large bipolarons in three and two dimensions”. Verbist G, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 43, 2712 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 155
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“Laser induced phase transition in iron thin films”. Teodorescu VS, Mihailescu IN, Dinescu M, Chitica N, Nistor LC, van Landuyt J, Barborica A, Journal de physique: 3: applied physics, materials science, fluids, plasma and instrumentation 4, 127 (1994). http://doi.org/10.1051/jp4:1994427
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 2
DOI: 10.1051/jp4:1994427
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“Lattice dynamics of a rotor-stator molecular crystal: Fullerene-cubane C60\centerdot C8H8”. Bousige C, Rols S, Cambedouzou J, Verberck B, Pekker S, Kováts É, Durkó, G, Jalsovsky I, Pellegrini É, Launois P, Physical review : B : condensed matter and materials physics 82, 195413 (2010). http://doi.org/10.1103/PhysRevB.82.195413
Abstract: The dynamics of fullerene-cubane (C60⋅C8H8) cocrystal is studied combining experimental [x-ray diffuse scattering, quasielastic and inelastic neutron scattering (INS)] and simulation (molecular dynamics) investigations. Neutron scattering gives direct evidence of the free rotation of fullerenes and of the libration of cubanes in the high-temperature phase, validating the rotor-stator description of this molecular system. X-ray diffuse scattering shows that orientational disorder survives the order/disorder transition in the low-temperature phase, although the loss of fullerene isotropic rotational diffusion is featured by the appearance of a 2.2 meV mode in the INS spectra. The coupling between INS and simulations allows identifying a degeneracy lift of the cubane librations in the low temperature phase, which is used as a tool for probing the environment of cubane in this phase and for getting further insights into the phase transition mechanism.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 16
DOI: 10.1103/PhysRevB.82.195413
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“Lattice thermal properties of graphane : thermal contraction, roughness, and heat capacity”. Neek-Amal M, Peeters FM, Physical review : B : condensed matter and materials physics 83, 235437 (2011). http://doi.org/10.1103/PhysRevB.83.235437
Abstract: Using atomistic simulations, we determine the roughness and the thermal properties of a suspended graphane sheet. As compared to graphene, we found that (i) hydrogenated graphene has a larger thermal contraction, (ii) the roughness exponent at room temperature is smaller, i.e., ≃ 1.0 versus ≃ 1.2 for graphene, (iii) the wavelengths of the induced ripples in graphane cover a wide range corresponding to length scales in the range 30125 Å at room temperature, and (iv) the heat capacity of graphane is estimated to be 29.32±0.23 J/mol K, which is 14.8% larger than that for graphene, i.e., 24.98±0.14 J/mol K. Above 1500 K, we found that graphane buckles when its edges are supported in the x-y plane.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 42
DOI: 10.1103/PhysRevB.83.235437
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“A layered iron-rich 2234-type with a mixed valence of iron: the ferrimagnetic Tl-doped Fe2(Sr2-\varepsilonTl\varepsilon)Sr3Fe4O14.65”. Lepoittevin C, Malo S, Nguyen N, Hebert S, Van Tendeloo G, Hervieu M, Chemistry of materials 20, 6468 (2008). http://doi.org/10.1021/cm8014385
Abstract: A new Tl-doped strontium ferrite Fe2(Sr2-Tl)Sr3Fe4O14.65, with an original structure, has been synthesized and structurally characterized by powder X-ray diffraction and transmission electron microscopy. The TGA and Mssbauer studies evidence a mixed valence of iron. The structure exhibits a commensurate modulation, with a F-type subcell a ≈ b ≈ 5.4 Å (≈ ap√2), c ≈ 42 Å with a modulation vector q = αa* with α = 0.4. The supercell parameters have been refined as a= 27.1101(8) Å, b= 5.5187(2) Å and c= 42.0513(9) Å, in the space group Fmmm. The electron diffraction and electron microscopy data of this novel ferrite show that it can be described as a FeTl-2234-type structure corresponding to the intergrowth of a quadruple perovskite slice [(SrFeO2.8)4], with a complex rock salt related slice [Fe2(Sr2-Tl)O3.4]∞, built up of one double iron layer [Fe2O2.4] sandwiched between two [SrO] layers. The HRTEM images show that the oxygen atoms and vacancies are randomly distributed in the perovskite layers while the HAADF STEM images evidence the absence of Tl segregation in the matrix. Fe2(Sr2-Tl)Sr3Fe4O14.65 exhibits a very large value of χ (11emu/mol) at 5 K, which remains large at 400 K; the M(H) loop presents a shape characteristic of ferrimagnetism, with a large coercive field of 0.3 T. The value of magnetization saturates at 400 K at 0.68 μB/Fe. At 10 K, the value of magnetization reaches a maximum of 2 μB/Fe. The resistivity presents a semiconducting-like behavior, with ρ 800 Ω·cm at 300 K.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 8
DOI: 10.1021/cm8014385
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“Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases”. Batuk M, Batuk D, Tsirlin AA, Filimonov DS, Sheptyakov DV, Frontzek M, Hadermann J, Abakumov AM, Chemistry of materials 27, 2946 (2015). http://doi.org/10.1021/acs.chemmater.5b00233
Abstract: New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 11
DOI: 10.1021/acs.chemmater.5b00233
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“Leached natural saponite as the silicate source in the synthesis of aluminosilicate hexagonal mesoporous materials”. Linssen T, Cool P, Baroudi M, Cassiers K, Vansant EF, Lebedev O, van Landuyt J, The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical 106, 4470 (2002). http://doi.org/10.1021/jp015578p
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Impact Factor: 3.177
Times cited: 23
DOI: 10.1021/jp015578p
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“Linear reduction of stiffness and vibration frequencies in defected circular monolayer graphene”. Neek-Amal M, Peeters FM, Physical review : B : condensed matter and materials physics 81, 11 (2010). http://doi.org/10.1103/PhysRevB.81.235437
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 44
DOI: 10.1103/PhysRevB.81.235437
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“Linking a completely three-dimensional nanostrain to a structural transformation eigenstrain”. Tirry W, Schryvers D, Nature materials 8, 752 (2009). http://doi.org/10.1038/NMAT2488
Abstract: NiTi is one of the most popular shape-memory alloys, a phenomenon resulting from a martensitic transformation. Commercial NiTi-based alloys are often thermally treated to contain Ni4Ti3 precipitates. The presence of these precipitates can introduce an extra transformation step related to the so-called R-phase. It is believed that the strain field surrounding the precipitates, caused by the matrixprecipitate lattice mismatch, lies at the origin of this intermediate transformation step. Atomic-resolution transmission electron microscopy in combination with geometrical phase analysis is used to measure the elastic strain field surrounding these precipitates. By combining measurements from two different crystallographic directions, the three-dimensional strain matrix is determined from two-dimensional measurements. Comparison of the measured strain matrix to the eigenstrain of the R-phase shows that both are very similar and that the introduction of the R-phase might indeed compensate the elastic strain introduced by the precipitate.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 39.737
Times cited: 53
DOI: 10.1038/NMAT2488
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“Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite”. Dachraoui W, Hadermann J, Abakumov AM, Tsirlin AA, Batuk D, Glazyrin K, McCammon C, Dubrovinsky L, Van Tendeloo G, Chemistry of materials 24, 1378 (2012). http://doi.org/10.1021/cm300178x
Abstract: The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 27
DOI: 10.1021/cm300178x
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“Low-energy-deposited Au clusters investigated by high-resolution electron microscopy and molecular dynamics simulations”. Pauwels B, Van Tendeloo G, Bouwen W, Kuhn LT, Lievens P, Lei H, Hou M, Physical review : B : condensed matter and materials physics 62, 10383 (2000). http://doi.org/10.1103/PhysRevB.62.10383
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 88
DOI: 10.1103/PhysRevB.62.10383
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“Low-strain Si/O superlattices with tunable electronic properties : ab initio calculations”. Nishio K, Lu AKA, Pourtois G, Physical review : B : condensed matter and materials physics 91, 165303 (2015). http://doi.org/10.1103/PhysRevB.91.165303
Abstract: We propose that low-strain Si/O superlattices can be constructed by connecting reconstructed Si{001} surfaces by Si-O-Si bridges. Ab initio calculations show that our models are energetically more favorable than all the models proposed so far. The part of our Si/O superlattice model is experimentally accessible just by oxidizing a Si( 001) substrate. To complete our Si/O superlattice model, we propose a three-step method. We also explore the potential of our Si/O superlattice models for new materials used in future Si electronics. We find that the location of the channel where the carriers travel can be controlled between the interfaces and the Si layers by the insertion of O atoms into the Si-Si dimers. By revealing the origins of the interface electron and hole states, we find that similar interface states should be easily achieved for Si slabs and Si substrates. Interestingly, the interface electrons and holes have small effective masses in the direction parallel to the channel and large effective masses in the direction normal to the channel, which makes the Si/O superlattices attractive to be used for channel materials. We also find that the valley splitting of Si is enhanced by the formation of the Si/O/Si interfaces, which is ideal for developing Si-based qubits. Our findings open new perspectives to design and control the electronic properties of Si.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.91.165303
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