Crystal structure and physical properties of the Sr-vacant spin-orbit-coupling induced Mott insulator Sr2-xIrO4

TL;DR

This study investigates the crystal structure and electronic properties of Sr2-xIrO4, revealing complex temperature-dependent conduction mechanisms and magnetic behavior influenced by strontium vacancies and spin-orbit coupling.

Contribution

It provides new insights into how Sr vacancies affect the structure and properties of Sr2-xIrO4, a spin-orbit-coupling induced Mott insulator.

Findings

Semiconducting behavior with variable range hopping at low temperatures

Observation of 2D weak localization at high temperatures

Antiferromagnetic order for x<0.30

Abstract

A series of polycrystalline samples of Sr2-xIrO4 have been synthesized by a solid-state reaction method. The crystal structure of this doped system can be explained on the basis of the extended nature of 5d electrons and strontium vacancies in Sr2-xIrO4. The analysis of the temperature-dependent resistance of these samples reveals the semiconducting feature, where three dimensional variable range hopping behavior is observed at temperatures lower than 120K, Arrhenius type in intermediate temperatures from 140K to 200K, and two-dimensional (2D) weak localization at high temperatures from 220K to 300K. Correspondingly, temperature-dependent magnetic properties in the range of x less than 0.30 can be described by the antiferromagnetically ordered spin system.