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Magnetoresistance and anomalous thermal hysteresis in La 0.67 Ca 0.33 MnO 3 /CaCu 3 Ti 4 O 12 composites
Author(s) -
Hua Luo Jiang,
Hua HeJing
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201026262
Subject(s) - magnetoresistance , materials science , electrical resistivity and conductivity , condensed matter physics , hysteresis , grain boundary , atmospheric temperature range , thermal hysteresis , diffraction , analytical chemistry (journal) , grain size , magnetic hysteresis , magnetic field , nuclear magnetic resonance , mineralogy , composite material , magnetization , microstructure , chemistry , phase transition , thermodynamics , electrical engineering , physics , optics , quantum mechanics , chromatography , engineering
The (1 − x ) La 0.67 Ca 0.33 MnO 3 (LCMO)/ x CaCu 3 Ti 4 O 12 (CCTO) ( x = 0, 0.01, 0.03, 0.05, and 0.10) composites were fabricated by the sol–gel method and investigated in detail for their electrical transport and magnetoresistance (MR) properties. The X‐ray diffraction and scanning electronic microscopy analysis reveal that both LCMO and CCTO phases are distributed in the composites. Compared with pure LCMO, an obvious enhancement of MR is observed over a wide temperature range for the composites at high external magnetic field. Under 3 T field, the MR increases to a maximum value of 73.4% for x = 0.1 composite. Simultaneously, the thermal hysteresis behavior in resistivity is observed in x = 0.03, 0.05, and 0.1 samples, respectively. The MR enhancement and the abnormal experimental observations are attributed to the enhanced spin disorder at grain boundaries induced by the interaction product layer between LCMO and CCTO.