Affiliation:
1. M.V. Lomonosov Moscow State University
Abstract
Thermopower α and magnetothermopower ∆α/α were studied in the Sm0.55Sr0.45MnO3 samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature TC = 126 K, A-type antiferromagnetic clusters with the Neel temperature TNA ≥ TC and CE-type antiferromagnetic clusters with the TNCE = 240 K. The curves of temperature dependence of α (T) have a large maximum including TC and TNCE and the sharp minimum on the {∆α/α}(T) curves in the TC-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.
Publisher
Trans Tech Publications, Ltd.
Subject
Condensed Matter Physics,General Materials Science,Atomic and Molecular Physics, and Optics
Reference8 articles.
1. A.I. Abramovich, L.I. Koroleva, A.V. Michurin, Zh. Eksp. Teor. Fiz. 95 (2002) 917.
2. V.V. Runov, D. Yu. Chernyshov, A.I. Kurbakov, M.K. Runova, V.A. Trunov, A.I. Okorokov, Zh. Eksp. Teor. Fiz. 91 (2000) 1017.
3. C. Martin, A. Maignan, M. Hervieu, B. Raveau, Phys. Rev. B 60 (1999) 12191.
4. V.V. Runov, G.P. Kopitsa, A.I. Okorokov, M.K. Runova, JETP Lett. 69 (1999) 353.
5. V. Runov, H. Glattli, G. Kopitsa, A. Okorokov, M. Runova, Physica, B276-278 (2000) 795.