Magnetocaloric and Colossal Magnetoresistance Effect in Layered Perovskite La_1.4 Sr_1.6Mn₂O₇

Li an Han 1,2) and Changle Chen 1) 1) School of science,Northwestern Polytechnical University,Xi an 710072,China 2) Department of applied physics,Xi an University of Science and Technology,Xi an 710054,China

摘 要：Magnetocaloric and colossal magnetoresistance effects of the layered perovskite La 1.4 Sr 1.6 Mn 2 O 7 compound have been studied.A broad peak of magnetic entropy change （-△S M） is found above the Curie temperature （T C =120 K）,which can be associated with the existence of two-dimensional short range ferromagnetic order.Additionally,the curvilinear shape of-△S M for layered perovskite is quite different from that of the Ln 1-x A x MnO 3 probably arising from magnetocrystalline anisotropy.At the same time,a wide peak of colossal magnetoresitance effect near T C is found in the layered provskite La 1.4 Sr 1.6 Mn 2 O 7.

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