Consequences of phase separation on magnetotransport in dc magnetron sputtered Sm0.50Sr0.50MnO3 thin films on LSAT substrate.

Single crystalline thin films of Sm 0.50 Sr 0.50 MnO 3 (SSMO) (thickness ∼200 nm) were prepared on LSAT (100) single crystal substrates by dc magnetron sputtering. The X-ray diffraction θ‒2θ and ω-2θ 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. Temperature and magnetic field dependent electrical transport of these films shows (i) sharp paramagnetic insulator (PMI) to ferromagnetic metal (FMM) transition, (ii) large enhancement in T IM when subjected to magnetic field, (iii) hysteretic variation in resistivity with magnetic field, and (iv) huge occurrence of magnetoresistance near PMI-FMM transition. The magnetic state in the FMM (T < T C ) regime resembles cluster glass, which is formed by the presence of charge ordered-antiferromagnetic clusters in the ferromagnetic matrix. The results shown in the present study could be regarded as the consequence of strong nature of phase separation in these films due to competing FMM and AFM-COI phases in these films which is known to be the generic feature of low bandwidth manganites. [ABSTRACT FROM AUTHOR]