Journal ArticleDOI
Two Spin-State Transitions in LaCoO 3
TLDR
In this paper, a new anomalous thermal lattice expansion of LaCoO 3 near 500 K was revealed, which indicates the existence of a second spin state transition, in addition to the one previously established near 100 K. The model parameters indicate that the initially large energy difference between IS and HS states decreases towards zero as the second transition proceeds.Abstract:
Neutron-diffraction measurements have revealed a new anomalous thermal lattice expansion of LaCoO 3 near 500 K that indicates the existence of a second spin-state transition, in addition to the one previously established near 100 K. The anomalous expansion and the temperature dependence of the Co magnetic moments are successfully interpreted in a wide temperature range based on a simple model assuming low-spin (LS, S =0), intermediate-spin (IS, S =1), and high-spin (HS, S =2) states of Co atoms. The first spin transition, near 100 K, is from LS to IS, and the second, near 500 K, is from IS to a mixed state of IS and HS. The fitted model parameters indicate that the initially-large energy difference between IS and HS states decreases towards zero as the second transition proceeds. The large drop in resistivity associated with the latter transition appears to be correlated with the population of the HS state.read more
Citations
More filters
Journal ArticleDOI
Electronic and ionic transport properties and other physical aspects of perovskites
TL;DR: The perovskites and their related structures exhibit several features of technical as well as fundamental interest, such as oxide-ion conduction with/without electronic conduction, oxidation catalysis, ferroic displacements in classic and relaxor ferroelectrics, half-metallic ferromagnetism and high-temperature superconductivity.
Posted Content
Intermediate-spin state and properties of LaCoO_3
TL;DR: The electronic structure of the perovskite LaCoO3 for different spin states of Co ions was calculated in the local-density approximation LDA+U approach and shows that Co 3d states of t(2g) symmetry form narrow bands which could easily localize, while e(g) orbitals, due to their strong hybridization with the oxygen 2p states, form a broad sigma* band.
Journal ArticleDOI
Evidence for orbital ordering in LaCoO3
TL;DR: In this article, powder and single-crystal x-ray diffraction data were used as evidence for a monoclinic distortion in the low-spin and intermediate spin states of the LaCoO ion.
Journal ArticleDOI
Spin-state transition in LaCoO3: direct neutron spectroscopic evidence of excited magnetic states.
Andrey Podlesnyak,S. Streule,Joël Mesot,Marisa Medarde,Ekaterina Pomjakushina,Kazimierz Conder,Arata Tanaka,Maurits W. Haverkort,D. I. Khomskii +8 more
TL;DR: This work interprets an excitation in LaCoO3 as originating from a transition between thermally excited states located about 120 K above the ground state, and discusses the nature of the magnetic excited state in terms of intermediate-spin versus high-spin states.
Journal ArticleDOI
Structure, magnetization, and resistivity of La 1 − x M x CoO 3 ( M = Ca , Sr, and Ba)
Markus Kriener,C. Zobel,A. Reichl,J. Baier,Matthias Cwik,K. Berggold,H. Kierspel,O. Zabara,A. Freimuth,Thomas Lorenz +9 more
TL;DR: In this article, the influence of structural distortions in charge-carrier doped by substituting alkaline-earth metals of strongly different ionic sizes was investigated. And the authors found that both the magnetic properties and the resistivity change non-monotonically as a function of the ionic size of M.
References
More filters
Journal ArticleDOI
On the Absorption Spectra of Complex Ions II
Yukito Tanabe,Satoru Sugano +1 more
TL;DR: In this paper, the authors solved the energy levels which are important in the absorption spectra of the normal complex ions, leaving the crystalline field strength as a parameter The values of B and C (Racah's parameters) there needed are determined from the observed spectras of free ions or in some cases by extrapolation The f -values of the transitions which connect energy levels calculated are estimated and compared with the observed intensities.
Journal ArticleDOI
First-order localized-electron collective-electron transition in LaCoO3
P. M. Raccah,John B. Goodenough +1 more
TL;DR: In this article, it is shown that the first-order phase change at the pseudocubic cell edge is continuous through the first order phase change, but the rhombohedral angle drops abruptly from 60.4 to 50.4 degrees.
Journal ArticleDOI
Intermediate-spin state and properties of LaCoO3.
TL;DR: In this article, the electronic structure of the perovskite LaCoO 3$ for different spin states of Co ions was calculated in the local density approximation LDA+U approach.
Posted Content
Intermediate-spin state and properties of LaCoO_3
TL;DR: The electronic structure of the perovskite LaCoO3 for different spin states of Co ions was calculated in the local-density approximation LDA+U approach and shows that Co 3d states of t(2g) symmetry form narrow bands which could easily localize, while e(g) orbitals, due to their strong hybridization with the oxygen 2p states, form a broad sigma* band.
Journal ArticleDOI
LaCoO{sub 3} revisited
TL;DR: In this article, homogeneous samples of LaCoO{sub 3} were prepared from coprecipitated precursors; they reveal that single-phase samples are restricted to a narrow range of the [La]/[Co] ratio of about 1.0.
Related Papers (5)
Structural phenomena associated with the spin-state transition in LaCoO 3
First-order localized-electron collective-electron transition in LaCoO3
P. M. Raccah,John B. Goodenough +1 more