Open AccessВлияние изовалентного замещения катионов на термические, калорические и магнетокалорические свойства манганитов (La-=SUB=-1-y-=/SUB=-Eu-=SUB=-y-=/SUB=-)-=SUB=-0.7-=/SUB=-Pb-=SUB=-0.3-=/SUB=-MnO-=SUB=-3-=/SUB=-
Author(s) -
А. В. Карташев,
И. Н. Флёров,
М. В. Горев,
Н. В. Михашенок
Publication year - 2019
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.01.46914.221
Subject(s) - magnetic refrigeration , manganite , materials science , solid solution , ferromagnetism , atmospheric temperature range , phase transition , thermodynamics , thermal expansion , analytical chemistry (journal) , intensity (physics) , condensed matter physics , chemistry , magnetic field , metallurgy , magnetization , physics , chromatography , quantum mechanics
Crystalline samples of the (La_1 – _ y Eu_ y )_0.7Pb_0.3MnO_3 ( y = 0, 0.2, 0.4, 0.5, 0.6, and 0.8) manganite solid solutions have been grown. Temperature dependences of the specific heat, thermal expansion, and high-intensity magnetocaloric effect have been investigated. A comparative analysis of the effect of isovalent cationic substitution on the thermal and caloric parameters of the ferromagnetic phase transition has been made. It has been shown that the growth of the Eu atom concentration leads to a decrease in the phase transition entropy and an increase in the baric coefficient dT / dp . Field and temperature dependences of the magnetocaloric effect have been established. It is demonstrated that, varying the ratio of cations, one can obtain the solid solutions with the maximum magnetocaloric effect value in fields of up to 6 kOe in a temperature range of 90–340 K. Owing to the similar reduced relative cooling powers, the investigated solid solutions can be used as reference solid-state cooling media in designing the cascade cooling systems.