Browsing School of Physics by Author "EDERER, CLAUDE"
Now showing items 1-20 of 29
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Ab initio electron theory for magnetism in Fe: Pressure dependence of spin-wave energies, exchange parameters, and Curie temperature
EDERER, CLAUDE (American Physical Society, 2003)The spin-wave spectra for bcc Fe at various lattice constants are calculated by the ab initio density functional electron theory for various lattice constants, and the exchange parameters of a Heisenberg model are determined ... -
Ab initio treatment of noncollinear spin systems within the atomic-sphere approximation and beyond
EDERER, CLAUDE (American Physical Society, 2000)The properties of noncollinear magnets are often calculated within the framework of density-functional theory in local-spin-density approximation with the additional use of the atomic-sphere approximation for the spin ... -
Anisotropy of orbital moments and magnetic dipole term Tz in CrO2. An ab initio study
EDERER, CLAUDE (American Physical Society, 2004)A systematic study is performed by the ab initio density-functional theory of the anisotropy of the orbital moments (lz) and the magnetic dipole term (Tz) in bulk CrO2. Two different band-structure techniques are used (full ... -
Calculation of model Hamiltonian parameters for LaMnO3 using maximally localized Wannier functions
EDERER, CLAUDE; KOVACIK, ROMAN (2010)In this work we demonstrate that maximally localized Wannier functions (MLWFs) based on Kohn-Sham band structures provide a very robust and systematic way to construct realistic, materials-specific tight-binding models for ... -
Correlation effects in p-electron magnets: the case of RbO_2
EDERER, CLAUDE (2009)We present results of GGA+U calculations for the "d^0 magnet" RbO_2, where magnetic properties are due to partially filled oxygen p orbitals. We show that on-site interactions on the oxygen sites lead to a strong tendency ... -
Density-functional study of Fe3AL: LSDA versus GGA
EDERER, CLAUDE (American Physical Society, 2002)The local-spin-density approximation and the generalized-gradient approximation ~GGA! are used to perform density-functional total-energy calculations at zero temperature for Fe3Al in the ordered D03 and L12 structures. ... -
Effect of epitaxial strain on the cation distribution in spinel ferrites CoFe(2)O(4) and NiFe(2)O(4): A density functional theory study
FRITSCH, DANIEL; EDERER, CLAUDE (American Institute of Physics, 2011)The effect of epitaxial strain on the cation distribution in spinel ferrites CoFe(2)O(4) and NiFe(2)O(4) is investigated by GGA+U total energy calculations. We obtain a very strong (moderate) tendency for cation inversion ... -
Effect of epitaxial strain on the spontaneous polarization of thin film ferroelectrics
EDERER, CLAUDE (American Physical Society, 2005)Epitaxial strain can substantially enhance the spontaneous polarizations and Curie temperatures of ferroelectric thin films compared to the corresponding bulk materials. In this Letter we use first principles calculations ... -
Effect of Hubbard U on the construction of low-energy Hamiltonians for LaMnO(3) via maximally localized Wannier functions
EDERER, CLAUDE; KOVACIK, ROMAN (American Physical Society, 2011)We use maximally localized Wannier functions to construct tight-binding (TB) parametrizations for the e(g) bands of LaMnO(3) based on first-principles electronic structure calculations. We compare two different ways to ... -
Electric-field-switchable magnets: The case of BaNiF4
EDERER, CLAUDE (American Physical Society, 2006)We show, using the antiferromagnetic ferroelectric BaNiF4 as a model system, that the ?weak? magnetic order arising from a polar structural distortion in a ferroelectric magnet due to the Dzyaloshinskii-Moriya interaction ... -
Experimental and computational investigation of structure and magnetism in pyrite Co1-xFexS2: Chemical bonding and half-metallicity
EDERER, CLAUDE (American Physical Society, 2004)Bulk samples of the pyrite chalcogenide solid solutions Co1?xFexS2 s0?x?0.5d, have been prepared and their crystal structures and magnetic properties studied by x-ray diffraction and SQUID magnetization measurements. Across ... -
Fast ab initio methods for the calculation of adiabatic spin wave spectra in complex systems
EDERER, CLAUDE (American Physical Society, 2001)The interpretation of the physics of magnets with reduced dimensionality often requires information on the spin wave excitations at arbitrary wavelengths which is generally hard to obtain experimentally. Two powerful methods ... -
First principles studies of multiferroic materials
EDERER, CLAUDE (2009)Multiferroics, materials where spontaneous long-range magnetic and dipolar orders coexist, represent an attractive class of compounds, which combine rich and fascinating fundamental physics with a technologically appealing ... -
First principles study of the multiferroics BiFeO3, Bi2FeCrO6, and BiCrO3: Structure, polarization, and magnetic ordering temperature
EDERER, CLAUDE (American Physical Society, 2005)We present results of an ab initio density-functional theory study of three bismuth-based multiferroics, BiFeO3, Bi2FeCrO6, and BiCrO3. We disuss differences in the crystal and electronic structure of the three systems and ... -
First-principles study of spontaneous polarization in multiferroic BiFeO3
EDERER, CLAUDE (American Physical Society, 2005)The ground-state structural and electronic properties of ferroelectric BiFeO3 are calculated using density functional theory within the local spin-density approximation (LSDA) and the LSDA + U method. The crystal structure ... -
First-principles study of the influence of (110)-oriented strain on the ferroelectric properties of rutile TiO2
EDERER, CLAUDE (American Physical Society, 2011)We use first-principles density-functional theory to investigate the softening of polar phonon modes in rutile TiO(2) under tensile (110)-oriented strain. We show that the system becomes unstable against a ferroelectric ... -
From the bulk to monatomic wires: An ab initio study of magnetism in Co systems with various dimensionality
EDERER, CLAUDE (American Physical Society, 2002)A systematic ab initio study within the framework of the local-spin-density approximation including spin-orbit coupling and an orbital-polarization term is performed for the spin and orbital moments and for the x-ray ... -
Influence of strain and oxygen vacancies on the magnetoelectric properties of multiferroic bismuth ferrite
EDERER, CLAUDE (American Physical Society, 2005)The dependencies on strain and oxygen vacancies of the ferroelectric polarization and the weak ferromagnetic magnetization in the multiferroic material bismuth ferrite, BiFeO3, are investigated using first principles density ... -
Magnetic coupling in Co Cr2 O4 and Mn Cr2 O4: An LSDA+U study
EDERER, CLAUDE (American Physical Society, 2007)We present a first principles LSDA+U study of the magnetic coupling constants in the spinel magnets CoCr2O4 and MnCr2O4. Our calculated coupling constants highlight the possible importance of AA interactions in spinel ...