ISSN:
1434-6036
Keywords:
PACS. 75.30.Sg Magnetocaloric effect, magnetic cooling – 82.80.-d Chemical analysis and related physical methods of analysis – 81.05.Mh Cermets, ceramic and refractory composites
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: Polycrystalline two-layered perovskite La2.5-xK0.5+xMn2O 7 + δ (0 〈 x 〈 0.5) samples have been prepared by a modified sol-gel method and their magnetoresistance and magnetocaloric effects have been studied. A large deviation between the metal-insulator (MI) transition temperature (T ρ ) and the magnetic transition temperature (TC) is observed. Large magnetoresistance (MR) effects with Δρ/ρ of ∼40% at 12 kOe are obtained in wide temperature ranges. The maximum of the magnetic entropy change peaks at its Curie temperature (TC), far above its MI transition temperature (T ρ ). The large magnetic entropy change (∼1.4 J/kg.K) is obtained in the sample La2.5-xK0.5+xMn2O 7 + δ (x = 0.35) upon 10 kOe applied magnetic field.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1140/epjb/e2002-00386-3
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