Giant Magnetothermopower in Sm_0.55Sr_0.45MnO₃ Manganite

Abstract:

Thermopower α and magnetothermopower ∆α/α were studied in the Sm_0.55Sr_0.45MnO₃ samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature T_C = 126 K, A-type antiferromagnetic clusters with the Neel temperature T_NA ≥ T_C and CE-type antiferromagnetic clusters with the T_NCE = 240 K. The curves of temperature dependence of α (T) have a large maximum including T_C and T_NCE and the sharp minimum on the {∆α/α}(T) curves in the T_C-region. Negative magnetothermopower in minimum achieves the giant value ~ 85% in magnetic field 14.17 kOe. It is shown that thermopower is largely caused by the presence of ferromagnetic nanoclusters of ferron-type and to a lesser degree of CE-type antiferromagnetic clusters, in which there is a charge ordering, displacing oxygen ions.

• Periodical: Solid State Phenomena (Volumes 233-234)
• Pages: 141-144
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.233-234.141
• Online since: July 2015
• Authors: Liudmila I. Koroleva*, Artiom S. Morozov, E.S. Zhakina
• Keywords: Charge, Crystallographic Heterogeneity, Magnetic, Magnetization, Magnetothermopower, Manganites, Paramagnetic Susceptibility, Thermopower

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