Srivastava, M. K. and Agarwal, V. and Kaur, A. and Singh, H. K.
(2017)
Colossal Magnetoresistance and Phase Separation in Manganite Thin Films.
In: 61ST DAE-SOLID STATE PHYSICS SYMPOSIUM, DEC 26-30, 2016, KIIT Univ, Bhubaneswar, INDIA.
Abstract
In the present work, polycrystalline Sm0.55Sr0.45MnO3 thin films were prepared on LSAT (001) single crystal substrates by ultrasonic nebulized spray pyrolysis technique. The X-ray diffraction theta-2 theta scan reveals that these films (i) have very good crystallinity, (ii) are oriented along out-of-plane c-direction, and (iii) are under small tensile strain. The impact of oxygen vacancy results into (i) higher value of paramagnetic insulator (PMI) to ferromagnetic metal (FMM) transition temperature, i. e., T-C/T-IM, (ii) sharper PMI-FMM transition, (iii) higher value of magnetization and magnetic saturation moment, and (iv) higher value of magnetoresistance (similar to 99%). We suggest here that oxygen vacancy favors FMM phase while oxygen vacancy annihilation leads to antiferromagnetic-charge ordered insulator (AFM-COI) phase. The observed results have been explained in context of phase separation (PS) caused by different fractions of the competing FMM and AFM-COI phases.
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