Magnetothermopower in Nd1-xEuxNiO3 compounds

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dc.creatorBarbeta, V. B.
dc.creatorJardim, R. F.
dc.creatorEscote, M. T.
dc.creatorDilley, N. R.
dc.date2007-03-20
dc.date.accessioned2026-07-07T07:52:45Z
dc.date.available2026-07-07T07:52:45Z
dc.descriptionWe have measured magnetization M(T,H), electrical resistivity ro(T,H), thermal conductivity k(T,H), and thermopower S(T,H) of polycrystalline samples of Nd1-xEuxNiO3; 0 <= x <= 0.35; as a function of temperature and external magnetic field. The data indicate a metal-insulator transition (MI) in a wide range of temperature (200 < TMI < 325 K). The magnetic susceptibility X(T) data, after the subtraction of the rare-earth contribution, exhibit a Curie-Weiss like behavior at temperatures above TMI. Although a clear antiferromagnetic AF transition of the Ni sub-lattice is observed at TN <= TMI, X(T) still increases down to 5 K, suggesting a heterogeneous ground state. The thermal conductivity of the NdNiO3 compound is not affected by an external magnetic field of 90 kOe in a wide range of temperature, and its temperature dependence below 15 K is approximately quadratic, strongly suggesting the presence of disorder. S(T) is negative above TMI and varies linearly with temperature. Below TMI, S(T) does not follow the expected behavior of insulating compounds. There is a minimum close to 120 K, and S(T) changes its sign at T ~ 30 K, indicating a competition between two types of charge carriers. A pronounced peak in S(T) at TS ~ 20 K does not follow the expected phonon-drag temperature dependence either above or below TS and the peak remains unaltered under magnetic fields up to 90 kOe. However, its magnitude is enhanced by ~ 25 % with applied magnetic field, exhibiting a clear magnetothermopower effect. The combined results indicate a coexistence of ordered and disordered phases below TN and that an applied magnetic field is suitable for enhancing the thermoelectric properties close to TS.
dc.description7 pages, 3 figures, and 1 table
dc.identifierhttps://arxiv.org/abs/cond-mat/0703512
dc.identifierhttp://arxiv.org/abs/cond-mat/0703512
dc.identifierdoi:10.1063/1.2710738
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/125996
dc.subjectStrongly Correlated Electrons
dc.subjectMaterials Science
dc.titleMagnetothermopower in Nd1-xEuxNiO3 compounds
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