Effect of substrate temperature on the structural and electrical properties of La and Mn co-doped BiFeO3 thin films

The effect of substrate temperature on the structural and electrical properties of multiferroic Bi0.90La0.10Fe0.95Mn0.05O3 (BLFMO) thin films deposited on Pt (111)/Ti/SiO2/Si substrate using pulsed laser deposition (PLD) has been investigated. Films with substrate temperature ranging from 450 degrees C to 650 degrees C have been deposited. The grain size and roughness are found to increase with substrate temperature. The film deposited at 575 degrees C exhibitsmaximumremnant polarization around 39 mu C/cm(2) and a coercive field of 400 kV/cm. The cyclic fatigue study of the sample shows only 4% loss after 10(8) cycles. Complex impedance study of the BLFMO thin films demonstrates electrical homogeneity of the sample. AC conductivity data has been fitted using Jonscher single power law, and value of n found to be <1 indicating translational hopping conduction mechanism. The lowest leakage current found is 4.37 x 10(-6) A/cm(2) at 575 degrees C. The leakage current mechanism is found to be dominated by space charge limited current and Fowler-Nordheim conduction mechanism. (C) 2016 Elsevier B.V. All rights reserved.