ScholarWorks@경상국립대학교

초록

The composite specimens of (1-x)(La0.7Sr0.3)MnO3-xBaTiO3 (x = 0.05 ~ 0.3) were synthesized using the conventional solid-state reaction method, and the sintering temperature and time were 1,300℃ and 3 hours, respectively. As a result of observing the structural characteristics, the crystal structure of LSMO-BT solid solution was shown in which the rhombohedral LSMO phase and the tetragonal BT phase were separated and distributed, respectively. And fine grains having relatively small and uniformly distributed grains with sizes ranging from approximately 0.4 to 0.5 μm and pores within the specimens were observed. Notably, variations in the BT content did not significantly affect the grain size or porosity distribution, and a relative density of about 90% or more was shown. The resistivity, temperature coefficient of resistance (TCR), and B25/65-value of the 0.7LSMO-0.3BT specimen at room temperature showed the highest values of 1.94 Ω-cm, 0.292 %/℃, and 464 K, respectively. The resistivity behavior of the LSMO–BT composites matched well with the small polaron hopping conduction model.

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