Anisotropic magnetic and magnetotransport properties in morphologically distinct Nd_0.6Sr_0.4MnO₃ thin films

Abstract We investigate the magnetic and magnetotransport properties of nanostructured Nd 0.6 Sr 0.4 MnO 3 (NSMO) thin films grown on (100) oriented SrTiO 3 (STO) substrates. The thin films of 100 nm thickness fabricated using the pulsed laser deposition technique possess two distinct surface morphologies—granular and nano-rod type. The morphological change present in the system significantly affects the magnetic and magnetotransport properties of the thin films. Magnetization measurements revealed that the films with rod-type morphology exhibit improved in-plane magnetic anisotropy. The colossal magnetoresistance (∆R/R(H = 0)) of the granular sample is ∼91 %, and the rod morphology sample is ∼97 % at 3 T magnetic field. Additionally, magnetotransport studies revealed that the granular thin films display a characteristic butterfly-shaped low-field magneto-resistive (LFMR) behavior with the value of LFMR of up to ∼10 %. Furthermore, it is observed that the thin film’s morphology has a significant effect on the anisotropic magnetoresistance ratio (AMR). Thin films with rod-type morphology show an enhanced AMR of ∼30 % around its metal-insulator transition temperature. Such morphology-dependent tunability in magnetoresistance properties over a wide temperature range is potentially interesting for developing oxide-based sensors and devices.