Itinerant metamagnetism and possible spin transition in LaCoO3 by temperature/hole doping
- 1 January 2002
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 91 (1), 291-303
- https://doi.org/10.1063/1.1418001
Abstract
The electronic structure of the perovskite has been obtained as a function of Sr substitution and volume from a series of generalized-gradient-corrected, full-potential, spin-density-functional band-structure calculations. The energetics of different spin configurations are estimated using the fixed-spin-moment (FSM) method. From the total energy versus spin magnetic moment curve for the ground state is found to be nonmagnetic with the Co ions in a low-spin (LS) state, a result that is consistent with the experimental observations. Somewhat higher in energy, we find an intermediate-spin (IS) state with spin moment From the anomalous temperature dependent susceptibility along with the observation of an IS state we predict metamagnetism in originating from an LS-to-IS transition. The IS state is found to be metallic and the high-spin (HS) state of is predicted to be a half-metallic ferromagnet. With increasing temperature, which is simulated by a corresponding change of the lattice parameters, we have observed the disappearance of the metamagnetic solution that is associated with the IS state. The FSM calculations on suggest that the hole doping stabilizes the IS state and the calculated magnetic moments are in good agreement with the corresponding experimental values. Our calculations show that the HS state cannot be stabilized by temperature or hole doping since the HS state is significantly higher in energy than the LS or IS state. Hence the spin-state transition in by temperature/hole doping is from an LS to an IS spin state and the present work rules out the other possibilities reported in the literature.
Keywords
This publication has 97 references indexed in Scilit:
- Neutron diffraction studies of perovskite-type compoundsJournal of Physics: Condensed Matter, 1996
- High-energy behavior of the double photoionization of helium from 2 to 12 keVPhysical Review A, 1993
- Full-potential, linearized augmented plane wave programs for crystalline systemsComputer Physics Communications, 1990
- Itinerant electron metamagnetism and spin fluctuations in nearly ferromagnetic metals Y(Co1-xAlx)2Journal of Physics: Condensed Matter, 1990
- Magnetism in fcc rhodium and palladiumPhysical Review B, 1989
- Possible highT c superconductivity in the Ba?La?Cu?O systemZeitschrift für Physik B Condensed Matter, 1986
- Electronic structure of lanthanum perovskites withtransition elementsPhysical Review B, 1980
- Magnetism of the rare earth, 3d – Theoretical reviewLe Journal de Physique Colloques, 1979
- Magnetic and electrical anomalies in LaCoO3Physica, 1964
- Magnetic compounds wtth perovskite structure III. ferromagnetic compounds of cobaltPhysica, 1953