Anisotropic resistivity of the antiferromagnetic insulator Bi_2Sr_2ErCu_2O_8

TL;DR

This study investigates the anisotropic electrical resistivity of Bi_2Sr_2ErCu_2O_8 single crystals, revealing unconventional conduction behavior in the antiferromagnetic insulator phase that differs from typical semiconductors.

Contribution

It provides detailed measurements and analysis of resistivity anisotropy in Bi_2Sr_2ErCu_2O_8, highlighting its unique conduction properties in the antiferromagnetic insulating state.

Findings

Resistivity is semiconducting in both directions but with different temperature dependencies.

Resistivity ratio peaks near room temperature for x=1.0.

Conduction behavior is unconventional compared to typical semiconductors.

Abstract

Anisotropic resistivities of Bi_2Sr_2Ca_{1-x}Er_xCu_2O_8 single crystals were measured and analyzed from 4.2 to 500 K with special interest in the parent antiferromagnetic insulator of x=1.0. Although the resistivity is semiconducting along both the in- and out-of-plane directions, the temperature dependence is found to be significantly different. As a result, the resistivity ratio for x=1.0 takes a broad maximum near room temperature. The electric conduction in parent antiferromagnetic insulators is different from other semiconductors, and is as unconventional as that in high-temperature superconductors.