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Related papers: Evidence for Multiple Phase Transitions in La_1-xC…

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We report thermal-expansion, lattice-constant, and specific-heat data of the series La_1-xA_xCoO_3 for 0<= x <= 0.30 with A = Ca, Sr, and Ba. For the undoped compound LaCoO_3 the thermal-expansion coefficient alpha(T) exhibits a pronounced…

Strongly Correlated Electrons · Physics 2015-05-13 M. Kriener , M. Braden , H. Kierspel , D. Senff , O. Zabara , C. Zobel , T. Lorenz

We present a study of the structure, the electric resistivity, the magnetic susceptibility, and the thermal expansion of La$_{1-x}$Eu$_x$CoO$_3$. LaCoO$_3$ shows a temperature-induced spin-state transition around 100 K and a metal-insulator…

Strongly Correlated Electrons · Physics 2009-11-10 J. Baier , S. Jodlauk , M. Kriener , A. Reichl , C. Zobel , H. Kierspel , A. Freimuth , T. Lorenz

The spin transition in LaCoO3 is investigated by temperature-dependent resonant soft X-ray emission spectroscopy near the Co 2p absorption edges. This element-specific technique is more bulk sensitive with respect to the temperature induced…

Strongly Correlated Electrons · Physics 2011-12-30 M. Magnuson , S. M. Butorin , C. Såthe , J. Nordgren , P. Ravindran

We present measurements of the magnetic susceptibility and of the thermal expansion of a LaCoO$_3$ single crystal. Both quantities show a strongly anomalous temperature dependence. Our data are consistently described in terms of a…

Strongly Correlated Electrons · Physics 2009-11-07 C. Zobel , M. Kriener , D. Bruns , J. Baier , M. Gr"uninger , T. Lorenz , P. Reutler , A. Revcolevschi

We present measurements of the thermal expansion coefficient alpha of polycrystalline LaFeAsO1-xFx (x <= 0.1). The magnetic and structural transitions of the samples with x <= 0.04 give rise to large anomalies in alpha(T), while the onset…

Superconductivity · Physics 2015-05-13 L. Wang , U. Kohler , N. Leps , A. Kondrat , M. Nale , A. Gasparini , A. de Visser , G. Behr , C. Hess , R. Klingeler , B. Buchner

The structural properties of LaCoO3 were studied by means of high-resolution neutron powder diffraction in the temperature range 5<T<1000 K. Changes of the Co+3 spin states in this temperature interval are shown to affect not only the unit…

Strongly Correlated Electrons · Physics 2009-11-07 Paolo G. Radaelli , Sang-Wook Cheong

The magnetic moment induced by an external magnetic field of 5.8 T on the Co3+ ions in LaCoO3 has been measured by polarized neutron diffraction. Measurements were made at 100 K, near to the spin-state transition, at 1.5 K and at 285 K. The…

Strongly Correlated Electrons · Physics 2015-06-25 V. P. Plakhty , P. J. Brown , B. Grenier , S. V. Shiryaev , S. N. Barilo , S. V. Gavrilov , E. Ressouche

A powder X-ray diffraction study, combined with the magnetic susceptibility and electric transport measurements, was performed on a series of LnCoO3 perovskites (Ln = Y, Dy, Gd, Sm, Nd, Pr and La) over a temperature range 100 - 1000 K. A…

Materials Science · Physics 2010-07-30 K. Knizek , Z. Jirak , J. Hejtmanek , M. Veverka , M. Marysko , G. Maris , T. T. M. Palstra

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…

Strongly Correlated Electrons · Physics 2007-05-23 György Vankó , Jean-Pascal Rueff , Aleksi Mattila , Zoltán Németh , Abhay Shukla

We present a combined study of the thermal expansion and the thermal conductivity of the perovskite series RCoO_3 with R = La, Nd, Pr and Eu. The well-known spin-state transition in LaCoO_3 is strongly affected by the exchange of the R ions…

Strongly Correlated Electrons · Physics 2010-01-04 K. Berggold , M. Kriener , P. Becker , M. Benomar , M. Reuther , C. Zobel , T. Lorenz

We present thermal expansion alpha, magnetostriction and specific heat C measurements of \tal, which shows a quantum phase transition from a spin-gap phase to a Neel-ordered ground state as a function of magnetic field around H_{C0}->4.8T.…

Strongly Correlated Electrons · Physics 2009-11-11 T. Lorenz , S. Stark , O. Heyer , N. Hollmann , A. Vasiliev , A. Oosawa , H. Tanaka

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(…

Strongly Correlated Electrons · Physics 2010-05-12 S. Ovchinnikov , Yu. Orlov , I. Nekrasov , Z. Pchelkina

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…

In the present work, we have reported the temperature dependent thermopower ($\alpha$) behavior of La$_{0.75}$Ba$_{0.25}$CoO$_{3}$ compound in the temperature range 300-600 K. Using the Heikes formula, the estimated value of $\alpha$…

Strongly Correlated Electrons · Physics 2017-04-25 Saurabh Singh , Devendra Kumar , Sudhir K. Pandey

Transport and magnetic measurements and structural and NMR studies have been carried out on (Pr1-yR'y)1-xAxCoO3 {R'=(rare earth elements and Y); A=(Ca, Ba and Sr)} at ambient pressure or under high pressure. The system exhibits a phase…

The spin state transition in LaCoO$_3$ has eluded description for decades despite concerted theoretical and experimental effort. In this study, we approach this problem using fully charge self-consistent Density Functional Theory + Embedded…

Materials Science · Physics 2017-11-15 Bismayan Chakrabarti , Turan Birol , Kristjan Haule

A high Seebeck coefficient (S), large electrical conductivity ({\sigma}), and reduced thermal conductivity ({\kappa}) are required to achieve a high figure-of-merit (zT) in an ideal thermoelectric (TE) system, which is challenging in a…

Materials Science · Physics 2023-03-09 Ashutosh Kumar , D. Sivaprahasam , Ajay D. Thakur

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 study the magnetic susceptibility of mixed-valent La2-xSrxCoO4 single crystals in the doping range of 0.5<= x <= 0.8 for temperatures up to 1000 K. The magnetism below room temperature is described by paramagnetic Co2+ in the high-spin…

Strongly Correlated Electrons · Physics 2012-04-04 N. Hollmann , M. W. Haverkort , M. Benomar , M. Cwik , M. Braden , T. Lorenz

Neutron diffraction for a polycrystalline sample of LaCo$_{0.8}$Rh$_{0.2}$O$_{3}$ and synchrotron x-ray diffraction for polycrystalline samples of LaCo$_{0.9}$Rh$_{0.1}$O$_{3}$ and LaCo$_{0.8}$Rh$_{0.2}$O$_{3}$ have been carried out in…

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