Electrical transport and 1/f noise properties of LaFe1-xNixO3 (x=0.3, 0.4 and 0.5) thin films

Abstract

The electrical transport and 1/f conduction noise properties of LaFe1-xNixO3 (x = 0.3, 0.4 and 0.5) thin films have been studied. The temperature dependent resistivity data have been fitted with Mott's variable-range hopping model. From the resistivity data we have estimated various parameters, namely, the hopping distance (R-h), the hopping energy (E-h) and the density of states at the Fermi level (N(E-F)). The decrease in the hopping energy and the increase in the density of states at room temperature have been observed with the increase in Ni doping for all samples. The Ni doping increases the density of charge carriers and enhances delocalization induced phenomena in the system. The magnitude of the normalized noise S-V/V-2 increases with the decrease in the Ni concentration over the whole temperature range. The conduction noise is also proportional to the square of the bias current, which confirms that the noise arises from the conduction fluctuations. The Hooge parameter (gamma) calculated at room temperature is compared with its value in semiconductors and manganite/oxide materials. The observed features have been explained on the basis of charge-carrier doping in LaFeO3. The noise measurements in conjugation with the electrical properties of the film propose the propitious characteristic of the system.