Effect of interface on temperature dependent magnetoresistance and room temperature magnetoimpedance of La0.7Sr0.3MnO3/Polyvinyl Alcohol nanocomposites

Abstract Interface effect on magnetotransport properties have been explored through proper tuning of Polyvinyl Alcohol concentration of 0.5%(S1),1%(S2) and 1.5%(S3) in La0.7Sr0.3MnO3(LSMO)-Polyvinyl Alcohol nanocomposites, prepared through solid state reaction route. Polyvinyl Alcohol chemisorbed grain boundaries (GB) of LSMO lead to distortion of Nyquist semicircles indicating non Debye type electrical relaxation process in the system. Decrease in GB resistance (R G B ) with magnetic field (H), indicates depinning of GB domain walls from GB pinning centers. Very small intergranular distance in clustered LSMO grains, seem to attribute minimum low frequency impedance in S3, amongst all the samples. Magnetoresistance (MR) studies indicate significant variation of MR with Polyvinyl Alcohol concentration at low temperature regime where efficient SPT in S3 due to cluster formation is strongly reflected. Dependence of surface spin magnetization on Polyvinyl Alcohol chemisorbed interface has been observed to be more dominating at low temperature region.