The crossover between two different conduction mechanisms (variable range and small polaron hoppings) is probed utilizing a conjunction of thermally varying conductivity and impedance in polycrystalline Pr2NiTiO6 (PNT). A combination of X-ray diffraction (XRD) and Raman spectroscopic investigations authenticates the lower symmetric monoclinic structure for PNT. The conductivity, impedance and relaxation spectra highlight the combined contributions of the electrodes, grain-boundaries and grain microstructures to the carrier dynamics in PNT. The relaxation mechanism has a non-ideal nature with distribution of relaxation times as observed from the dielectric and impedance spectroscopic data. The dc resistivity investigation points towards a transition in the conduction mechanism showing a gradual crossover at temperature 490 K, from small polaron hopping to Mott s variable range hopping due to reduced activation energy.
@article{arxiv.1707.02830,
title = {Temperature dependent conductivity mechanisms observed in Pr2NiTiO6},
author = {Moumin Rudra and Saswata Halder and Sujoy Saha and Alo Dutta and T. P. Sinha},
journal= {arXiv preprint arXiv:1707.02830},
year = {2019}
}