Low temperature synthesis and pressure induced insulator-metal transition of the newly found NdFeAsO0.75

TL;DR

This study reports the low-temperature synthesis of NdFeAsO0.75 and its pressure-induced transition from insulator-like to metal-like electrical behavior, highlighting a novel synthesis approach and phase transition.

Contribution

It introduces a low-temperature synthesis method for NdFeAsO0.75 without mineralizers and demonstrates a pressure-induced insulator-metal transition.

Findings

Successful synthesis at 900°C with high phase purity

Pressure treatment induces insulator-metal transition

Lowest reported synthesis temperature for this compound

Abstract

As low as 900 oC, iron-based layered quaternary compound NdFeAsO0.75 was synthesized through solid state reaction method. XRD measurements illustrate almost pure phase of tetragonal phase NdFeAsO was formed. The synthesis temperature in our experiment is the lowest among all the reported methods without the help of any mineralizer. After further treatment under high pressure of 6 GPa at temperature of 1300 oC for 2 hours, the electrical transport property of NdFeAsO0.75 was transformed from insulator-like to metal- like behavior.