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ENHANCEMENT OF FERROMAGNETIC CLUSTER INDUCED BY MAGNETIC FIELD IN THE PHASE-SEPARATED La0.5Ca0.5MnO3
Li Run-wei (李润伟), Sun Ji-rong (孙继荣), Wang Zhi-hong (王志宏), Chen Xin (陈新), Zhang Shao-ying (张绍英), Shen Bao-gen (沈保根)
Chinese Physics, 2000, 9 (8):
630-633.
DOI: 10.1088/1009-1963/9/8/015
Magnetic and transport properties of La0.5Ca0.5MnO3 have been investigated by measuring the magnetization and resistance in zero-field-cooled (ZFC) and field-cooled (FC) modes. Conspicuously irreversible behaviors of magnetization/resistance in the two different modes were observed below the charge ordering transition temperature (TCO). The ZFC and FC magnetizations at 5K, as functions of the magnetic field, coincide for $\mu$0H≤1T. Afterwards, the ZFC magnetization tends to an approximate constant, but the FC one increases linearly with increasing field. There exists an excellent correspondence between magnetization and resistance below TCO. All the results suggest that the ferromagnetic clusters embed in the charge-ordered matrix. The phenomenon of ferromagnetic clusters growing up easily in the FC procedure has been interpreted according to the model of thermally activated two-level system.
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