MAGNETOCALORIC PROPERTIES OF THE LA0.7-XYXSR0.3MNO3 GIANT MAGNETORESISTANCE CERAMICS

Giant magnetoresistance (GMR), observed in several La(0.7x)A(0.3)MnO(3 ) ceramics, where A is a two-valent addition, is the result of an inte raction of conduction electrons and intrinsic magnetization, which is likely to result in unusual magnetocaloric effects. On this basis, mag netization, magnetic entropy change and adiabatic temperature change w ere measured as a function of Y content in La0.7-xYxSr0.3MnO3 ceramics . It is found that doping influences only the transition temperature, while the magnetic entropy change remains constant and displays a satu ration tendency in high fields. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.