Electronic properties and the nature of metal-insulator transition in NdNiO3 prepared at ambient oxygen pressure

TL;DR

This study investigates the electronic properties and metal-insulator transition of NdNiO3 prepared at ambient oxygen pressure, revealing a transition at 192 K and unique conduction mechanisms at low temperatures.

Contribution

It provides new insights into the electronic behavior and phase transition characteristics of NdNiO3 synthesized under ambient oxygen conditions.

Findings

Metal-insulator transition at 192 K observed.

Low temperature state less insulating than high-pressure samples.

Charge transport dominated by variable range hopping at 2-20 K.

Abstract

We report the electronic properties of the NdNiO3, prepared at the ambient oxygen pressure condition. The metal-insulator transition temperature is observed at 192 K, but the low temperature state is found to be less insulating compared to the NdNiO3 prepared at high oxygen pressure. The electric resistivity, Seebeck coefficient and thermal conductivity of the compound show large hysteresis below the metal-insulator transition. The large value of the effective mass (m* ~ 8me) in the metallic state indicate the narrow character of the 3d band. The electric conduction at low temperatures (T = 2 - 20 K) is governed by the variable range hopping of the charge carriers.