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相关论文: Spin-state transition and spin-polaron physics in …

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We present an inelastic neutron scattering study of the low energy crystal-field excitations in the lightly doped cobalt perovskite La_0.998Sr_0.002CoO_3. In contrast to the parent compound LaCoO_3 an inelastic peak at energy transfer ~0.75…

强关联电子 · 物理学 2008-02-22 A. Podlesnyak , K. Conder , E. Pomjakushina , A. Mirmelstein , P. Allenspach , D. I. Khomskii

We report the continuous variation of the spin moment of cobalt in LaCoO3 across its temperature and pressure-induced spin transitions evidenced with K\beta emission spectra. The first thermal transition is best described by a transition to…

强关联电子 · 物理学 2007-05-23 György Vankó , Jean-Pascal Rueff , Aleksi Mattila , Zoltán Németh , Abhay Shukla

The electronic structure of the perovskite LaCoO$_3$ for different spin states of Co ions was calculated in the LDA+U approach. The ground state was found to be a nonmagnetic insulator with Co ions in a low-spin state. Somewhat higher in…

强关联电子 · 物理学 2008-02-03 M. A. Korotin , S. Yu. Ezhov , I. V. Solovyev , V. I. Anisimov , D. I. Khomskii , G. A. Sawatzky

The doping series Eu1-xCaxCoO3-d provides a rather peculiar way to study the spin-state transition in cobalt-based complex oxides since partial substitution of Eu3+ ions by Ca2+ ions does not increase the mean valence state of cobalt but is…

We present first principles LDA+U calculations of electronic structure and magnetic state for LaCoO3 and HoCoO3. Low Spin to Intermediate Spin state transition was found in our calculations using experimental crystallographic data for both…

强关联电子 · 物理学 2009-11-10 I. A. Nekrasov , S. V. Streltsov , M. A. Korotin , V. I. Anisimov

Spin-state ordering - a periodic pattern of ions with different spin-state configurations along a crystal lattice - is a rare phenomenon, and its possible interrelation with other electronic degrees of freedom remains little explored. Here…

强关联电子 · 物理学 2024-03-27 E. Granado , C. W. Galdino , B. D. Moreno , G. King , D. C. Freitas

The electronic structure of the perovskite La$_{1-x}$Sr$_x$CoO$_3$ 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…

强关联电子 · 物理学 2009-11-07 P. Ravindran , H. Fjellvåg , A. Kjekshus , P. Blaha , K. Schwarz , J. Luitz

The interplay between crystal electric field splitting of d states and Hund's rule exchange energy in cobalt-based perovskites offers a promising avenue for inducing spin-state transitions. This study reports a new body-centered tetragonal…

Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-$L_{2,3}$ edge we reveal that the spin state transition in LaCoO$_{3}$ can be well described by a low-spin ground state and a triply-degenerate high-spin…

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…

材料科学 · 物理学 2014-11-12 M. Rotter , Z. -S. Wang , A. T. Boothroyd , D. Prabhakaran , A. Tanaka , M. Doerr

We carried out temperature-dependent (20 - 550 K) measurements of resonant inelastic X-ray scattering on LaCoO$_3$ to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer…

The spin states and electronic structure of layered perovskite La1.5Ca0.5CoO4 are investigated using fullpotential linearized augmented plane-wave method. All the computational results indicate that the Co2+ ion is in a high-spin state and…

强关联电子 · 物理学 2013-05-29 Ting Jia , Hua Wu , Guoren Zhang , Xiaoli Zhang , Ying Guo , Zhi Zeng , H. Q. Lin

The samples LaCoO3 with dilute substitutions on cobalt sites have been studied using the resistivity, thermopower and magnetic susceptibility measurements over the temperature range up to ~900 K. The Co-site substitution does not affect the…

材料科学 · 物理学 2010-07-30 J. Hejtmanek , Z. Jirak , K. Knizek , M. Marysko , M. Veverka , C. Autret

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…

Spin-state crossover beyond a conventional ligand-field theory has been a fundamental issue in condensed matter physics. Here, we report microscopic observations of spin states and low-energy dynamics through orbital-resolved NMR…

Magnetization measurements of LaCoO$_{3}$ have been carried out up to 133 T generated with a destructive pulse magnet at a wide temperature range from 2 to 120 K. A novel magnetic transition was found at $B>100$ T and $T>T^{*}=32\pm 5$ K…

强关联电子 · 物理学 2016-06-15 Akihiko Ikeda , Toshihiro Nomura , Yasuhiro H. Matsuda , Akira Matsuo , Koichi Kindo , Keisuke Sato

Using density functional theory within the LSDA + U method, we investigate the effect of strain on the spin state and magnetic ordering in perovskite lanthanum cobaltite, LaCoO3. We show that, while strain-induced changes in lattice…

材料科学 · 物理学 2009-02-18 James M. Rondinelli , Nicola A. Spaldin

For many years a spin-state transition at $T \approx 100 K$ and insulator - metal transition (IMT) at $T_{IMT} \approx 600 K$ in LaCoO$_3 $ remains a mystery. Small low-spin - high-spin spin gap $\Delta _S = E\left( {HS} \right) - E\left(…

强关联电子 · 物理学 2010-05-12 S. Ovchinnikov , Yu. Orlov , I. Nekrasov , Z. Pchelkina

A gradual spin-state transition occurs in LaCoO3 around T~80-120 K, whose detailed nature remains controversial. We studied this transition by means of inelastic neutron scattering (INS), and found that with increasing temperature an…

强关联电子 · 物理学 2008-02-22 A. Podlesnyak , S. Streule , J. Mesot , M. Medarde , E. Pomjakushina , K. Conder , M. W. Haverkort , D. I. Khomskii

The electronic and magnetic states in doped perovskite cobaltites, (La, Sr)CoO_3, are studied in the numerically exact diagonalization method on Co_2O_{11} clusters. For realistic parameter values, it is shown that a high spin state and an…

强关联电子 · 物理学 2009-10-31 K. Tsutsui , J. Inoue , S. Maekawa
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