The effect of quenched disorder caused by oxygen vacancies and substrate-induced inhomogeneous compressive strain, on the magnetic and transport properties of oriented polycrystalline Sm0.55Sr0.45MnO3 thin films was investigated. quenched disorder was related intimately to the ordering/disordering of the oxygen vacancies and controlled the paramagnetic-ferromagnetic/insulator-metal transition. Oxygen vacancy-ordered films showed enhanced TC/TIM ∼ 165K, which was depressed by oxygen annealing. Oxygen vacancy-disordering realized by quenching reduced TC/TIM. The first-order insulator-metal transition observed in Sm0.55Sr0.45MnO3 single crystals was transformed into non-hysteretic and continuous one in the oxygen vacancy-ordered films. Quenched disorder appeared to be diluted by oxygen vacancy-disorder/annihilation and resulted in stronger carrier localization.

Enhanced Ferromagnetic and Metal Insulator Transition in Sm0.55Sr0.45MnO3 Thin Films: Role of Oxygen Vacancy Induced Quenched Disorder. M.K.Srivastava, P.K.Siwach, A.Kaur, H.K.Singh: Applied Physics Letters, 2010, 97[18], 182503