Magnetic and electrical properties of LaCoO3 - LaNiO3 epitaxial thin films on LaAlO3 substrate

Abstract

The mixed transition metal oxide thin films having ABO3 structure noticed numerous applications due to their robust electrical and magnetic properties. Among them, Lanthanum cobalt oxide considered as promising material since it exhibits excellent properties as catalyst and mixed ionic-electronic conductors. In this manuscript, we successfully deposited the epitaxial lanthanum cobalt oxide (LaCoO3) and lanthanum nickel oxide (LaNiO3) thin films on single crystal lanthanum aluminate (LAO) substrate. Individual and bilayer thin films are grown by pulsed laser deposition (PLD). X-ray diffraction pattern reveals the epitaxial nature and phase purity of the deposited thin films. Morphological images has been captured using field-emission scanning electron microscopy (FE-SEM). The electrical and magnetic properties of individual and bilayer LaCoO3/LaNiO3 thin films are measured using four-probe and physical property measurement system (PPMS) respectively. There is a clear ferromagnetic transition in LaCoO3 thin film observed at 85 K. Surprisingly, the bilayer of LaNiO3/LaCoO3 thin films exhibited enhanced magnetic properties compared with individual LaCoO3 or LaNiO3 thin films. The bilayer films revealed the high magnetization and less coercive filed (3.76 emu/cm3, 2215H) respectively. These results given an idea that bilayer LaCoO3/LaNiO3 thin films are capable to exhibit enhanced multifunctional properties.