Effect of film thickness on electrical and magneto-transport properties in Pr0.5Sr0.5MnO3 thin films grown on LaAlO3 (0 1 1)

Abstract

Thin films of Pr0.5Sr0.5MnO3 of various thickness (16 nm, 25 nm, 40 nm and 70 nm) have been deposited on LaAlO3 (011). The 16 nm, 25 nm, and 70 nm films show semiconducting-insulating behaviour at 0 T and 5 T magnetic fields. The 40 nm film shows melting of charge ordering and occurrence of metal to insulator transition at temperature 178 (230) K at 0 (5) T. The magnetic field reduces the resistivity showing a significant magnetoresistance (MR). The high-temperature semiconducting resistivity is governed by variable range hopping (VRH) transport mechanism, whereas the metallic region in 40 nm film follows empirical relation of a third-order polynomial. The insulating electrical behaviour and metal–insulator transition are observed to depend on the nature of substrate-induced strain that is experienced by the film.