Structural and electronic properties of Titanium doped LaNiO3 thin films

Abstract

Perovskite oxides exhibit lot of practical applications that make them a potential candidate for physics now a days. Rare earth nickelates RNiO3 show phase transition, strongly correlated effects, Colossal Magnetoresistance, high temperature superconductivity etc. All these properties are highly controllable in thin film form. In the phase diagram of RNiO3, LaNiO3 does not show metal to insulator transition. We have deposited thin films of LaNi1-xTixO3 (x=0- 0.10) on LaAlO3 (001) (LAO) single crystal substrate using pulsed laser deposition method and studied the effect of Ti doping on structural and electronic properties. All the films are highly oriented towards the (001) substrate axis. The resistivity measurements indicate that the films remains metallic even at low temperature range and there is no metal to insulator transition observed. Although, the resistivity of the system increases with doping. The power law fitting of resistivity data shows the non-Fermi behaviour of the system. With doping, blueshift of Raman modes is observed that indicates change in Ni-O-Ni bond angle and NiO6 octahedra distortion. Temperature dependent Raman spectroscopy show the red shift in all the thin films. It helps to study the effects of Ti doping on the structural and electronic properties of LaNiO3.