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Related papers: Intermediate-spin state and properties of LaCoO_3

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We sought the origin of the metal-insulator transition in Sr2-xLaxCoO4, using electron-correlation corrected density functional calculations. Our results show that Sr2CoO4 is in an intermediate-spin (IS) state and a strong Co4+ 3d-O 2p…

Strongly Correlated Electrons · Physics 2015-06-11 Hua Wu

We have calculated the discrete low-energy electronic structure in LaMnO3 originating from the atomic-like states of the strongly correlated 3d4 electronic system occurring in the Mn3+ ion. We take into account very strong intra-atomic…

Strongly Correlated Electrons · Physics 2009-11-10 R. J. Radwanski , Z. Ropka

In the scientific description of unconventional transport properties of oxides (spin-dependent transport, superconductivity etc.), the spin-state degree of freedom plays a fundamental role. Because of this, temperature- or magnetic…

Materials Science · Physics 2014-11-12 M. Rotter , Z. -S. Wang , A. T. Boothroyd , D. Prabhakaran , A. Tanaka , M. Doerr

Neutron diffraction studies have been carried out on a single crystal of oxygen-deficient perovskite TbBaCo2O5.5 in the temperature range of 7-370 K. There have been observed several magnetic or structural transitions. Among these, the…

Strongly Correlated Electrons · Physics 2009-11-10 Minoru Soda , Yukio Yasui , Toshiaki Fujita , Takeshi Miyashita , Masatoshi Sato , Kazuhisa Kakurai

The insulating ground state of the 5d transition metal oxide CaIrO3 has been classified as a Mott-type insulator. Based on a systematic density functional theory (DFT) study with local, semilocal, and hybrid exchange-correlation…

Strongly Correlated Electrons · Physics 2015-09-04 Sun-Woo Kim , Chen Liu , Hyun-Jung Kim , Jun-Ho Lee , Yongxin Yao , Kai-Ming Ho , Jun-Hyung Cho

We present an ab initio study of double perovskite La$_2$VCuO$_6$, which was one of the earliest compounds suggested as a potential compensated half-metal. Two charge and spin configurations close in energy have been identified. (i) The…

Strongly Correlated Electrons · Physics 2012-06-29 Victor Pardo , Warren E. Pickett

Ultra-high resolution synchrotron diffraction data for $\rm GdBaCo_2O_{5.5}$ throw new light on the metal-insulator transition of Co$^{3+}$ Ba-cobaltites. An anomalous expansion of CoO$_6$ octahedra is observed at the phase transition on…

Materials Science · Physics 2016-08-16 C. Frontera , J. L. García-Muñoz , A. Llobet , M. A. G. Aranda

We have performed calculations of the electronic structure of LaCoO3 from first principles, assuming the atomistic construction of matter and the electrostatic origin of the crystal-field splitting. In our atomic-like approach QUASST the d…

Strongly Correlated Electrons · Physics 2007-05-23 R. J. Radwanski , Z. Ropka

Spin-state transition, also known as spin crossover, plays a key role in diverse systems, including minerals and biological materials. In theory, the boundary range between the low- and high-spin states is expected to enrich the transition…

We investigate lattice dynamics in LaCoO$_3$ using inelastic neutron and x-ray scattering over $T = 2\mbox{-}650\,\mathrm{K}$, spanning the spin-state crossover at $T_{1} \approx 100\,\mathrm{K}$ and the insulator--metal transition at…

To describe the metal insulator transition in the new oxide TlSr2CoO5 we investigate its electronic structure by LDA and model Hartree-Fock calculations. Within LDA we find a homogeneous metallic and ferromagnetic ground state, but when…

Strongly Correlated Electrons · Physics 2009-10-31 D. Foerster , R. Hayn , T. Pruschke , H. Rosner , M. Zoelfl

Using Co-L_(2,3) and O-K x-ray absorption spectroscopy, we reveal that the charge ordering in La_(1.5)Sr_(0.5)CoO4 involves high spin (S=3/2) Co^2+ and low spin (S=0) Co^3+ ions. This provides evidence for the spin blockade phenomenon as a…

Strongly Correlated Electrons · Physics 2009-03-16 C. F. Chang , Z. Hu , Hua Wu , T. Burnus , N. Hollmann , M. Benomar , T. Lorenz , A. Tanaka , H. -J. Lin , H. H. Hsieh , C. T. Chen , L. H. Tjeng

With local density approximation + Hubbard $U$ (LDA+$U$) calculations, we show that the ferromagnetic (FM) insulating state observed in tensile-strained LaCoO$_3$ epitaxial thin films is most likely a mixture of low-spin (LS) and high-spin…

Strongly Correlated Electrons · Physics 2022-05-20 Han Hsu , Peter Blaha , Renata M. Wentzcovitch

Transport, thermal and magnetic measurements have been carried out on (Pr1-ySmy)1-xCaxCoO3. The system exhibits a structural phase transition accompanied by the spin state change from the intermediate spin (IS) state to the low spin (LS)…

Strongly Correlated Electrons · Physics 2009-11-11 Toshiaki Fujita , Shohei Kawabata , Masatoshi Sato , Nobuyuki Kurita , Masato Hedo , Yoshiya Uwatoko

Using soft-x-ray absorption spectroscopy at the Co-$L_{2,3}$ and O-$K$ edges, we demonstrate that the Co$^{3+}$ ions with the CoO$_{5}$ pyramidal coordination in the layered Sr$_2$CoO$_3$Cl compound are unambiguously in the high spin state.…

Strongly Correlated Electrons · Physics 2007-05-23 Z. Hu , Hua Wu , M. W. Haverkort , H. H. Hsieh , H. -J. Lin , T. Lorenz , J. Baier , A. Reichl , I. Bonn , C. Felser , A. Tanaka , C. T. Chen , L. H. Tjeng

We use the LDA+U approach to search for possible ordered ground states of LaSrCoO$_4$. We find a staggered arrangement of magnetic multipoles to be stable over a broad range of Co $3d$ interaction parameters. This ordered state can be…

Strongly Correlated Electrons · Physics 2018-03-19 J. Fernández Afonso , A. Sotnikov , J. Kuneš

The variational cluster approximation is applied to the calculation of thermodynamical quantities and single-particle spectra of LaCoO3. Trial self-energies and the numerical value of the Luttinger-Ward functional are obtained by exact…

Strongly Correlated Electrons · Physics 2015-05-14 R. Eder

We present an ab initio study of the (001) interfaces between two insulating perovskites, the polar LaAlO3 and the nonpolar SrTiO3. We observe an insulating-to-metallic transition above a critical LaAlO3 thickness. We explain that the high…

Materials Science · Physics 2009-11-13 Hanghui Chen , Alexie M. Kolpak , Sohrab Ismail-Beigi

Using density functional theory plus Hubbard $U$ calculations, we show that the ground state of (Mg,Fe)(Si,Fe)O$_3$ perovskite, a major mineral phase in the Earth's lower mantle, has high-spin ferric iron ($S=5/2$) at both the dodecahedral…

Geophysics · Physics 2015-05-27 Han Hsu , Peter Blaha , Matteo Cococcioni , Renata M. Wentzcovitch

Recently, the perovskite BiCoO$_3$ has been shown experimentally to be isostructural with PbTiO$_3$, while simultaneously the $d^6$ Co$^{3+}$ ion has a high spin ground state with $C$-type antiferromagnetic ordering. Using hybrid density…

Materials Science · Physics 2016-05-04 Leigh Weston , Xiangyuan Cui , Simon P. Ringer , Catherine Stampfl