“Hysteresis and reentrant melting of a self-organized system of classical particles confined in a parabolic trap”. Munarin FF, Nelissen K, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 77, 031608 (2008). http://doi.org/10.1103/PhysRevE.77.031608
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.77.031608
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“Surface enhanced Raman scattering of silver sensitized cobalt nanoparticles in metaldielectric nanocomposites”. Margueritat J, Gonzalo J, Afonso CN, Hörmann U, Van Tendeloo G, Mlayah A, Murray DB, Saviot L, Zhou Y, Hong MH, Luk'yanchuk BS, Nanotechnology 19, 375701 (2008). http://doi.org/10.1088/0957-4484/19/37/375701
Abstract: We report the preparation of a new type of nanocomposite containing cobalt and silver nanoparticles organized in parallel layers with a well controlled separation. This arrangement allows the observation of an enhanced low-frequency Raman signal at the vibration frequency of cobalt nanoparticles excited through the surface plasmons of silver nanoparticles. Numerical simulations of the electric field confirm the emergence of hot spots when the separation between silver and cobalt nanoparticles is small enough.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.44
Times cited: 11
DOI: 10.1088/0957-4484/19/37/375701
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“Calculation of binary and ternary metallic immiscible clusters with icosahedral structures”. Dzhurakhalov AA, Atanasov I, Hou M, Physical review : B : condensed matter and materials physics , 115415 (2008). http://doi.org/10.1103/PHYSREVB.77.115415
Abstract: Recently, core-shell Ag-Co, Ag-Cu, and “onionlike” Cu-Co equilibrium configurations were predicted in the case of isolated face centered cubic (fcc) bimetallic clusters, and three shell onionlike configurations were predicted in the case of ternary metallic clusters with spherical and truncated octahedral morphologies. In the present paper, immiscible binary CuCo and ternary AgCuCo clusters with icosahedral structures are studied as functions of their size and composition. Clusters studied are formed by 13, 55, 147, 309, and 561 atoms corresponding to the five smallest possible closed shell icosahedral structures. An embedded atom model potential is used to describe their cohesion. Equilibrium configurations are investigated by means of Metropolis Monte Carlo free energy minimization in the (NPT) canonical ensemble. Most simulations are achieved at 10 and 300 K. The effect of temperature on segregation ordering is systematically investigated. Selected cases are used to identify the effect of size and composition on melting. In contrast with fcc clusters, homogeneous onionlike configurations of binary clusters are not predicted. When it is allowed by the composition, a complete outer shell is formed by Cu in binary Cu-Co clusters and by Ag in ternary Ag-Cu-Co clusters. Depending on temperature, Co may precipitate into decahedral groups under the Cu vertices of the icosahedra in binary clusters, while the Co-Cu configuration in ternary clusters drastically depends on the Ag coating. Despite the multicomponent character of the clusters and the immiscibility of the species forming them, for most compositions and sizes, equilibrium structures remain close to perfectly icosahedral at 10 K as well as at 300 K.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.836
Times cited: 11
DOI: 10.1103/PHYSREVB.77.115415
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“Dynamics of periodic anticrossings: decoherence, pointer states, and hysteresis curves”. Földi P, Benedict MG, Peeters FM, Physical review : A : atomic, molecular and optical physics 77, 013406 (2008). http://doi.org/10.1103/PhysRevA.77.013406
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.925
Times cited: 10
DOI: 10.1103/PhysRevA.77.013406
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“Melting of anisotropically confined Coulomb balls”. Apolinario SWS, Peeters FM, Physical review : B : condensed matter and materials physics 78, 024202 (2008). http://doi.org/10.1103/PhysRevB.78.024202
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.78.024202
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“Microstructure and high temperature transport properties of high quality epitaxial SrFeO3-\delta films”. Solís C, Rossell MD, Garcia G, Figueras A, Van Tendeloo G, Santiso J, Solid state ionics 179, 1996 (2008). http://doi.org/10.1016/j.ssi.2008.06.004
Abstract: We report the high temperature electronic transport properties of SrFeO3 − ä epitaxial thin films obtained by pulsed laser deposition on NdGaO3(110) substrates. The films show total conductivity higher than the bulk material and apparent activation energy of about 0.12 eV in O2, lower than reported values for SrFeO3 − ä films. The conductivity dependence with oxygen partial pressure shows a power dependence with an exponent close to + 1/4, in agreement with expected point defect equilibrium. For a given oxygen partial pressure, the temperature coefficient of resistance (TCR) shows a low positive value of about 1.52.5 10− 3 K− 1, which is still suitable for resistive oxygen sensing applications. The transport properties of the films are discussed in view of their particular microstructure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.354
Times cited: 10
DOI: 10.1016/j.ssi.2008.06.004
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“Unusual strain accommodation and conductivity enhancement by structure modulation variations in Sr4Fe6O12+\delta epitaxial films”. Solís C, Rossell MD, Garcia G, Van Tendeloo G, Santiso J, Advanced functional materials 18, 785 (2008). http://doi.org/10.1002/adfm.200701011
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 12.124
Times cited: 10
DOI: 10.1002/adfm.200701011
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“Monte Carlo analysis of the electron thermalization process in the afterglow of a microsecond dc pulsed glow discharge”. Martín A, Bordel N, Pereiro R, Bogaerts A, Spectrochimica acta: part B : atomic spectroscopy 63, 1274 (2008). http://doi.org/10.1016/j.sab.2008.09.012
Abstract: A Monte Carlo model is utilized for studying the behavior of electrons in the afterglow of an analytical microsecond dc pulsed glow discharge. This model uses several quantities as input data, such as electric field and potential, ion flux at the cathode, the fast argon ion and atom impact ionization rates, slow electron density, the electrical characterization of the pulse (voltage and current profiles) and temperature profile. These quantities were obtained by earlier Monte Carlo fluid calculations for a pulsed discharge. Our goal is to study the behavior of the so-called Monte Carlo electrons (i.e., those electrons created at the cathode or by ionization collisions in the plasma which are followed by using the Monte Carlo model) from their origin to the moment when they are absorbed at the cell walls or when they have lost their energy by collisions (being transferred to the group of slow electrons) in the afterglow of the pulsed discharge. The thermalization of the electrons is a phenomenon where the electron-electron Coulomb collisions acquire a special importance. Indeed, in the afterglow the cross sections of the other electron reactions taken into account in the model are very low, because of the very low electron energy. We study the electron energy distributions at several times during and after the pulse and at several positions in the plasma cell, focusing on the thermalization and on the behavior of the electrons in the afterglow. Also, the time evolution of the rates of the various collision processes, the average electron energy, the densities of Monte Carlo and slow electrons and the ionization degree are investigated.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.241
Times cited: 9
DOI: 10.1016/j.sab.2008.09.012
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“Relaxation phenomena at the metal-to-insulator transition in La0.8Sr0.2MnO3 single crystals”. Dominiczak M, Ruyter A, Limelette P, Monot-Laffez I, Giovannelli F, Rossell MD, Van Tendeloo G, Solid state communications 148, 340 (2008). http://doi.org/10.1016/j.ssc.2008.08.029
Abstract: The time dependence of the resistance RAC of a La0.8Sr0.2MnO3 single crystal has been investigated in the vicinity of the metal-to-insulator transition temperature. We used local probe microscopy to show the existence, at room temperature, of coexisting clusters of micrometer size. Our analysis shows that relaxation effects can be described with a simple exponential contribution using a random resistor-network, based on phase separation between insulating and metallic domains. Our results clearly prove the existence of a percolation threshold over which no percolation path exists. Moreover, these results highlight the significant role of the remanent magnetization.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.554
Times cited: 9
DOI: 10.1016/j.ssc.2008.08.029
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“Resonant tunneling in graphene microstructures”. Milton Pereira J, Vasilopoulos P, Peeters FM, Microelectronics journal 39, 534 (2008). http://doi.org/10.1016/j.mejo.2007.07.099
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.163
Times cited: 9
DOI: 10.1016/j.mejo.2007.07.099
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“Size-dependence of vortex shells in mesoscopic superconducting disks”. Misko VR, Xu B, Peeters FM, Physica: C : superconductivity 468, 726 (2008). http://doi.org/10.1016/j.physc.2007.11.036
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 9
DOI: 10.1016/j.physc.2007.11.036
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“Synthesis and characterization of oxygen-deficient oxides BaCo1-xYxO3-y' x = 0.15, 0.25 and 0.33, with the perovskite structure”. Lomakov MV, Istomin SY, Abakumov AM, Van Tendeloo G, Antipov EV, Solid state ionics 179, 1885 (2008). http://doi.org/10.1016/j.ssi.2008.05.004
Abstract: Oxygen-deficient complex cobalt oxides BaCo1 − xYxO3 − y, = 0.15, 0.25 and 0.33, with a cubic perovskite structure have been synthesized in air at 1100 °C using a citrate route. Cation composition of the compounds was confirmed by energy-dispersed X-ray (EDX) microanalysis while oxygen content was determined by iodometric titration. An electron diffraction (ED) study of the x = 0.25 and 0.33 compositions show the presence of a diffuse intensity, indicating possible short-range ordering of the B cations. It was found that the treatment of BaCo0.75Y0.25O2.55 in a humid atmosphere leads to the absorption of water vapour at the first stage. Oxygen permeation studies of the ceramic membranes of BaCo0.75Y0.25O2.55 and BaCo0.67Y0.33O2.55 with variable thickness showed high oxygen fluxes of 0.170.32 µmol/cm2/s at 950 °C.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.354
Times cited: 9
DOI: 10.1016/j.ssi.2008.05.004
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“Conductance of a copper-nanotube bundle interface: impact of interface geometry and wave-function interference”. Compemolle S, Pourtois G, Sorée B, Magnus W, Chibotaru LF, Ceulemans A, Physical review : B : condensed matter and materials physics 77, 193406 (2008). http://doi.org/10.1103/PhysRevB.77.193406
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.836
Times cited: 8
DOI: 10.1103/PhysRevB.77.193406
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“Crosshatching on La0.5Ca0.5MnO3 ultrathin films epitaxially grown on SrTiO3(100)”. Wang Z-H, Lebedev OI, Van Tendeloo G, Cristiani G, Habermeier H-U, Physical review : B : condensed matter and materials physics 77, 1 (2008). http://doi.org/10.1103/PhysRevB.77.115330
Abstract: The morphological evolution in La(0.5)Ca(0.5)MnO(3)/SrTiO(3)(100) ultrathin films has been revealed by atomic force microscopy. It was found that ordered linear defects, which are in 1-2 unit cells high and oriented along the cubic [110] and [100] directions, first appear on the smooth surface of films with a thickness of 10 nm. As the epitaxial growth proceeds, these lines on surface develop into a crosshatch pattern for films with a thickness of 25 nm. Using the results of transmission electron microscopy and electrical measurements, we discuss the interplay between the surface pattern formation, the internal dislocation structure, and the variations in the electrical properties.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 8
DOI: 10.1103/PhysRevB.77.115330
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“Effect of annealing on cold-rolled Ni-Ti alloys”. Srivastava AK, Yang Z, Schryvers D, van Hurnbeeck J, Materials science and engineering: part A: structural materials: properties, microstructure and processing 481, 594 (2008). http://doi.org/10.1016/j.msea.2006.12.216
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.094
Times cited: 8
DOI: 10.1016/j.msea.2006.12.216
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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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“Magneto-optical imaging of flux penetration into arrays of Bi2Sr2CaCu2O8 microdisks”. Connolly MR, Milošević, MV, Bending SJ, Tamegai T, Physical review : B : solid state 78, 132501 (2008). http://doi.org/10.1103/PhysRevB.78.132501
Abstract: We have used differential magneto-optical (MO) imaging to investigate the mixed state of superconducting Bi2Sr2CaCu2O8+ (BSCCO) microdisks fabricated on a single-crystal sample. MO difference images of the stray field distribution over a range of out-of-plane fields allow us to distinguish between flux that is penetrating the disks and that entering the underlying BSCCO platelet. We find that flux preferentially flows along linear defects into the interstitial platelet regions up to a characteristic field Hp, above which flux enters the disks. We identify this as the field of first penetration of pancake vortices over the Bean-Livingston barrier around the disks, where Hp(T) at intermediate temperatures is well described by an exponentially decaying function with a characteristic temperature T0=19 K. At a given temperature, a minority of the disks exhibit a lower penetration field and we correlate the location of these disks with the linear defects in the BSCCO crystal.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 8
DOI: 10.1103/PhysRevB.78.132501
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“Quantum transport in an ultra-thin SOI MOSFET: influence of the channel thickness on the I-V characteristics”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Magnus W, Schoenmaker W, Sorée B, Solid state communications 147, 31 (2008). http://doi.org/10.1016/j.ssc.2008.04.025
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 1.554
Times cited: 8
DOI: 10.1016/j.ssc.2008.04.025
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“Two-level anti-crossings high up in the single-particle energy spectrum of a quantum dot”. Payette C, Austing DG, Yu G, Gupta JA, Nair SV, Partoens B, Amaha S, Tarucha S, Physica. E: Low-dimensional systems and nanostructures 40, 1807 (2008). http://doi.org/10.1016/j.physe.2007.09.060
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 8
DOI: 10.1016/j.physe.2007.09.060
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“Electron energy-loss spectroscopy study of NiTi shape memory alloys”. Yang ZQ, Schryvers D, Materials science and engineering: part A: structural materials: properties, microstructure and processing 481, 214 (2008). http://doi.org/10.1016/j.msea.2006.12.227
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.094
Times cited: 7
DOI: 10.1016/j.msea.2006.12.227
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“First-principles study of doped Si and Ge nanowires”. Peelaers H, Partoens B, Peeters FM, Physica. E: Low-dimensional systems and nanostructures 40, 2169 (2008). http://doi.org/10.1016/j.physe.2007.10.090
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 7
DOI: 10.1016/j.physe.2007.10.090
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“The martensitic phase transition in Ni-Al: experimental observation of excess entropy and heterogeneous spontaneous strain”. Zhang H, Salje EKH, Schryvers D, Bartova B, Journal of physics : condensed matter 20, 055220 (2008). http://doi.org/10.1088/0953-8984/20/5/055220
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 7
DOI: 10.1088/0953-8984/20/5/055220
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“Oxygen vacancy ordering in the double-layered Ruddlesden-Popper cobaltite Sm2BaCo2O7-\delta”. Gillie LJ, Hadermann J, Hervieu M, Maignan A, Martin C, Chemistry of materials 20, 6231 (2008). http://doi.org/10.1021/cm8010138
Abstract: A new oxygen-deficient Ruddlesden−Popper (RP) cobaltite Sm2BaCo2O7−δ (δ ≈ 1.0) has been synthesized and the crystal structure elucidated by Rietveld analysis of X-ray powder diffraction (XRD) data and transmission electron microscopy (TEM). The phase crystallizes in a primitive orthorhombic unit cell, with lattice parameters a = 5.4371(4) Å; b = 5.4405(4) Å and c = 19.8629(6) Å, and space group Pnnm. Contrary to other oxygen-deficient cobalt RP phases, the oxygen vacancies are located in the equatorial positions of the [CoO] layers to give an intralayer structure similar to Sr2Mn2O5, which is not usually observed for cobalt-containing materials. The Sm3+ and Ba2+ cations show a strong preference for distinct sites, with the majority of the larger Ba2+ cations situated in the perovskite block layers and Sm3+ cations predominantly in the rock salt layers. Magnetic susceptibility data demonstrate the strong antiferromagnetic (AFM) character of Sm2BaCo2O7−δ.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 7
DOI: 10.1021/cm8010138
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“Advantages of combined mu-XRF and mu-XRD for phase characterization of Ti-B-C ceramics compared with conventional X-ray diffraction”. Jaroszewicz J, de Nolf W, Janssens K, Michalski A, Falkenberg G, Analytical and bioanalytical chemistry 391, 1129 (2008). http://doi.org/10.1007/S00216-008-2097-6
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.431
Times cited: 7
DOI: 10.1007/S00216-008-2097-6
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“mu-X-ray fluorescence and mu-X-ray diffraction investigations of sediment from the Ruprechtov nuclear waste disposal natural analog site”. Denecke MA, de Nolf W, Janssens K, Brendebach B, Falkenberg G, Noseck U, Rothkirch A, Spectrochimica acta: part B : atomic spectroscopy 63, 484 (2008). http://doi.org/10.1016/J.SAB.2008.01.001
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.241
Times cited: 7
DOI: 10.1016/J.SAB.2008.01.001
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“Fullerene-cubane : X-ray scattering experiments and Monte Carlo simulations”. Verberck B, Heresanu V, Rouziere S, Cambedouzou J, Launois P, Kovats E, Pekker S, Vliegenthart GA, Michel KH, Gompper G, Fullerenes, nanotubes, and carbon nanostructures
T2 –, 8th Biennial International Workshop on Fullerenes and Atomic Clusters, (IWFAC 2007), JUL 02-06, 2007, St Petersburg, RUSSIA 16, 293 (2008). http://doi.org/10.1080/15363830802205830
Abstract: We report single-crystal X-ray diffuse scattering measurements on C-60.C8H8 fullerene-cubane showing that the C-60 molecules are orientationally disordered at 300 and 150K and get ordered at low temperatures. Monte Carlo simulations provide further insight in the orientational behavior of both C-60 and C8H8 molecules; low-temperature molecular orientations are predicted.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 1.35
Times cited: 6
DOI: 10.1080/15363830802205830
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“Modeling of a dielectric barrier discharge used as a flowing chemical reactor”. Petrović, D, Martens T, van Dijk J, Brok WJM, Bogaerts A, Journal of physics : conference series 133, 012023 (2008). http://doi.org/10.1088/1742-6596/133/1/012023
Abstract: Our aim is to develop and optimize a model for a dielectric barrier discharge used as a chemical reactor for gas treatment. In order to determine the optimum operating conditions, we have studied the influence of the gas flow rate, reactor geometry and applied voltage parameters on the discharge characteristics. For this purpose, a two-dimensional time-dependent fluid model has been applied to an atmospheric pressure DBD in helium with nitrogen impurities, in a cylindrical geometry. The numerical model is based on the continuity and flux equations for each type of particles treated, the electron energy equation and the Poisson equation. The gas flow is incorporated in the flux equations as a source term. The set of coupled partial differential equations is solved by the so-called modified strongly implicit method. The background gas flow is numerically treated separately, assuming in the model that there is no influence of the plasma on the flow. Indeed, the gas convection velocity is calculated using the commercial code Fluent and it is used as input into the 2D fluid model. The plasma characteristics have been studied in terms of gas flow rate, applied voltage amplitude and frequency, and geometrical effects. The electric currents as a function of time for a given applied potential have been obtained, as well as the number densities and fluxes of plasma species.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 6
DOI: 10.1088/1742-6596/133/1/012023
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“Nanoscale superconductivity: nanowires and nanofilms”. Shanenko AA, Croitoru MD, Peeters FM, Physica: C : superconductivity 468, 593 (2008). http://doi.org/10.1016/j.physc.2007.11.053
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 1.404
Times cited: 6
DOI: 10.1016/j.physc.2007.11.053
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“New germanates RCrGeO5 (R=NdEr, Y): synthesis, structure, and properties”. Shpanchenko RV, Tsirlin AA, Kondakova ES, Antipov EV, Bougerol C, Hadermann J, Van Tendeloo G, Sakurai H, Takayama-Muromachi E, Journal of solid state chemistry 181, 2433 (2008). http://doi.org/10.1016/j.jssc.2008.05.043
Abstract: The new complex germanates RCrGeO5 (R=NdEr, Y) have been synthesized and investigated by means of X-ray powder diffraction, electron microscopy, magnetic susceptibility and specific heat measurements. All the compounds are isostructural and crystallize in the orthorhombic symmetry, space group Pbam, and Z=4. The crystal structure of RCrGeO5, as refined using X-ray powder diffraction data, includes infinite chains built by edge-sharing Cr+3O6 octahedra with two alternating Cr−Cr distances. The chains are combined into a three-dimensional framework by Ge2O8 groups consisting of two edge-linked square pyramids oriented in opposite directions. The resulting framework contains pentagonal channels where rare-earth elements are located. Thus, RCrGeO5 germanates present new examples of RMn2O5-type compounds and show ordering of Cr+3 and Ge+4 cations. Electron diffraction as well as high-resolution electron microscopy confirm the structure solution. Magnetic susceptibility data for R=Nd, Sm, and Eu are qualitatively consistent with the presence of isolated 3d (antiferromagnetically coupled Cr+3 cations) and 4f (R+3) spin subsystems in the RCrGeO5 compounds. NdCrGeO5 undergoes long-range magnetic ordering at 2.6 K, while SmCrGeO5 and EuCrGeO5 do not show any phase transitions down to 2 K.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 6
DOI: 10.1016/j.jssc.2008.05.043
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“Direct observation of nanometer-scale pinning sites in (Nd0.33Eu0.20Gd0.47)Ba2Cu3O7-\delta single crystals”. Das P, Koblischka MR, Turner S, Van Tendeloo G, Wolf T, Jirsa M, Hartmann U, Europhysics letters 83, 37005 (2008). http://doi.org/10.1209/0295-5075/83/37005
Abstract: We report on the observation of self-organized stripe-like structures on the as-grown surface and in the bulk of (Nd,Eu,Gd)Ba2Cu3Oy single crystals. The periodicity of the stripes on the surface lies between 500800 nm. These are possibly the growth steps of the crystal. Transmission electron microscopy investigations revealed stripes of periodicity in the range of 2040 nm in the bulk. From electron back scattered diffraction investigations, no crystallographic misorientation due to the nanostripes has been found. Scanning tunneling spectroscopic experiments revealed nonsuperconducting regions, running along twin directions, which presumably constitute strong pinning sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.957
Times cited: 5
DOI: 10.1209/0295-5075/83/37005
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