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connecion of thermopower and giant magnetothermopower with magnetic and structural heterogeneity in Sm0.55Sr0.45MnO3 manganiteстатья
Информация о цитировании статьи получена из
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 30 марта 2016 г.
- Авторы: Koroleva L.I., Morozov A.S., Jakhina E.s., Balbashov A.M.
- Журнал: Journal of Magnetism and Magnetic Materials
- Том: 396
- Номер: 1
- Год издания: 2015
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 146
- Последняя страница: 152
- DOI: 10.1016/jmmm.2015.08.033
- Аннотация: It was first shownthat the thermoelectric power in a magnetic semiconductorSm0.55Sr0.45MnO3 is caused by ferromagnetic (FM) ferron-type nanoclusters and antiferromagnetic (AFM) CE-type nanoclusters with charge-orbital (CO) ordering . The presence of these clusters is caused by heavity Sr doping of a SmMnO3 compound, which replaced Sm ions. Thermelectric power S and magnetothermopower deltaS/S has been studied in three samples: ceramics and two single-crystal samples. One of single-crystals was cooled in the air, another one was cooled in an oxygen atmosphere.The annealing in oxygen closes oxygen vacancies and thus increases the fraction of the CE-type AFM phase with the CO ordering which displaces the the oxygen ions.S(T) curves of single-crystal sample cooled in the air and ceramic sample have a sharp increase starting from Curie temperature (T_C) region and a slow decine till 325 K.At the same time (deltaS/S)(T)curves have a sharp minimum near T_C = 126 K reaching the giant absolute value of 87% in magnetic field H = 14,17 kOe. This means that thermopower almost vanish with thermal destruction of FM clusters. , i.e. thermopower is caused by these clusters in which crystallattice is compressed. Oxygen cooled single-crystal"s S(T) curves have a broad maximum near 270 R, including Neel temperature of CE-type clusters T_NCE= 240 K.(delta S/S)(T) curve has a sharp minimum at the T_NCE reaching the absolute value of 50% in H= 13.2 kOe. The decrease of S is caused by destruction of CO-order displacing oxygen ions in CE-type AFM clusters. Thus changed crystal lattice in nanoclusters of ferron type or AFM of CE-type makes the main contridution in thermopower in these three samples.
- Добавил в систему: Королёва Людмила Ивановна