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Related papers: Enhanced thermopower via spin-state modification

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Two samples of the [Ca$_2$CoO$_{3-t}$]$_{0.62}$(CoO$_2$) misfit cobaltate, often denoted as the Ca$_{3}$Co$_{3.93}$O$_{9}$ phase, were prepared from the same ceramic material by the oxygen and argon annealing, resulting in different carrier…

Materials Science · Physics 2015-09-30 J. Hejtmánek , Z. Jirák , J. Šebek

We present the study of magnetization, thermal expansion, specific heat, resistivity, and a.c. susceptibility of (Pr$_{1-y}$Eu$_y$)$_{0.7}$Ca$_{0.3}$CoO$_3$ cobaltites. The measurements were performed on ceramic samples with $y = 0.12 -…

We investigate both thermoelectric and thermodynamic properties of the misfit cobalt oxide [Bi$_{1.7}$Co$_{0.3}$Ca$_{2}$O$_{4}$]$^{RS}_{0.6}$CoO$_{2}$. A large negative magnetothermopower is found to scale with both magnetic field and…

Strongly Correlated Electrons · Physics 2007-05-23 P. Limelette , S. Hebert , V. Hardy , R. Fresard , Ch. Simon , A. Maignan

Resistivity and dc magnetization measurements were performed for the polycrystalline Pr$_{0.5}$Ca$_{0.5}$Co$_{1-x}$Fe$_{x}$O$_{3-\delta}$ ($x$ = 0, 0.05, 0.10 and 0.15) samples. The as-fabricated samples exhibit ferromagnetic (FM)…

Strongly Correlated Electrons · Physics 2009-11-11 X. G. Luo , X. Li , G. Y. Wang , G. Wu , X. H. Chen

We have investigated the effect of pressure on the electronic, magnetic, and structural properties on a single crystal of conducting, ferromagnet (T$_{C}$=157K) La$_{0.82}$Sr$_{0.18}$CoO$_{3}$ located near the boundary of the…

Strongly Correlated Electrons · Physics 2009-11-11 R. Lengsdorf , M. Ait-Tahar , S. S. Saxena , M. Ellerby , D. I. Khomskii , H. Micklitz , T. Lorenz , M. M. Abd-Elmeguid

The magnetic glassy state is a fascinating phenomenon, which results from the kinetic arrest of the first order magnetic phase transition. Interesting properties, such as metastable magnetization and nonequilibrium magnetic phases, are…

Heat-to-charge conversion efficiency of thermoelectric materials is closely linked to the entropy per charge carrier. Thus, magnetic materials are promising building blocks for highly efficient energy harvesters, as their carrier entropy is…

Using analytical arguments and the numerical renormalization group method we investigate the spin-thermopower of a quantum dot in a magnetic field. In the particle-hole symmetric situation the temperature difference applied across the dot…

Mesoscale and Nanoscale Physics · Physics 2012-02-24 Tomaz Rejec , Rok Zitko , Jernej Mravlje , Anton Ramsak

Magnetic, dielectric, and magnetoelectric properties in a spin-state transition system are examined, motivated by the recent discovery of a multiferroic behavior in a cobalt oxide. We construct an effective model Hamiltonian based on the…

Strongly Correlated Electrons · Physics 2018-06-13 Makoto Naka , Eriko Mizoguchi , Joji Nasu , Sumio Ishihara

We study the spin thermopower in the two-channel spin-1/2 Kondo model which exhibits the phenomenon of impurity spin overscreening and non-Fermi-liquid properties. While magnetic field lower than the Kondo temperature does not strongly…

Strongly Correlated Electrons · Physics 2013-12-06 Rok Zitko , Jernej Mravlje , Anton Ramsak , Tomaz Rejec

We investigate the spin Seebeck effect and spin pumping in a junction between a ferromagnetic insulator and a magnetic impurity deposited on a normal metal. By the numerical renormalization group calculation, we show that spin current is…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 Tsuyoshi Yamamoto , Takeo Kato , Mamoru Matsuo

We report measurements and analysis of magnetization, resistivity and thermopower of polycrystalline samples of the perovskite-type Co/Rh oxide La$_{0.8}$Sr$_{0.2}$Co$_{1-x}$Rh$_x$O$_{3-\delta}$. This system constitutes a solid solution for…

Strongly Correlated Electrons · Physics 2015-05-19 S. Shibasaki , I. Terasaki , E. Nishibori , H. Sawa , J. Lybeck , H. Yamauchi , M. Karppinen

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

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

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 this paper we investigate the spin-resolved thermoelectric properties of strongly correlated molecular junctions in the linear response regime. The magnetic molecule is modeled by a single orbital level to which the molecular core spin…

Mesoscale and Nanoscale Physics · Physics 2021-05-25 Anand Manaparambil , Ireneusz Weymann

We investigate the Sn-substitution effect on the thermoelectric transport properties of the layered cobaltite [Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$] single crystals, which exhibit a non-monotonic temperature variation of the electrical…

Strongly Correlated Electrons · Physics 2025-11-04 Motoya Takenaka , Shogo Yoshida , Yoshiki J. Sato , Ryuji Okazaki

A wide family of cobalt oxides of formulation (Pr,Ln,Ca)CoO3 (Ln being a lanthanide) exhibits a coupled valence and spin-state transition (VSST) at a temperature T*, which involves two concomitant modifications: (i) a change in the spin…

Strongly Correlated Electrons · Physics 2015-06-15 V. Hardy , F. Guillou , Y. Bréard

An important contribution to the thermoelectric and spin-caloric transport properties in magnetic materials at elevated temperatures is the formation of a spin-disordered state due to local moment fluctuations. This effect has not been…

Materials Science · Physics 2015-06-23 Roman Kováčik , Phivos Mavropoulos , Stefan Blügel

We theoretically investigate the thermoelectric and spin thermoelectric properties of a T-shaped double quantum dot strongly coupled to two ferromagnetic leads, focusing on transport regime where the system exhibits the two-stage Kondo…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 Krzysztof P. Wójcik , Ireneusz Weymann
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