Large magnetoresistance anomalies in Dy7Rh3

TL;DR

This study investigates the large and unusual magnetoresistance effects in Dy7Rh3, revealing significant MR anomalies across a broad temperature range, including above the magnetic ordering temperature, due to magnetic field influences.

Contribution

It reports the discovery of large magnetoresistance anomalies in Dy7Rh3, especially at moderate magnetic fields and temperatures above the Néel temperature, which is uncommon in intermetallic compounds.

Findings

Large MR observed at moderate fields (80 kOe) above T_N.

Suppression of resistivity peak at high magnetic fields.

Unusual MR behavior across the entire temperature range studied.

Abstract

The compound Dy7Rh3 ordering antiferromagnetically below (TN=) 59 K has been known to exhibit a temperature (T) dependent electrical resistivity (rho) behavior in the paramagnetic state unusual for intermetallic compounds in the sense that there is a broad peak in rho(T) in the paramagnetic state (around 130 K) as though there is a semi-conductor to metal transition. In addition, there is an upturn below T_N due to magnetic super-zone gap effects. Here we report the influence of external magnetic field (H) on the rho(T) behavior of this compound below 300 K. The rise of rho(T) found below TN could be suppressed at very high fields (>> 60 kOe), thus resulting in a very large magnetoresistance (MR) in the magnetically ordered state. The most notable finding is that the magnitude of MR is large for moderate applications of H (say 80 kOe) in a temperature range far above T_N as well, which is untypical of intermetallic compounds. Thus, this compound is characterized by large MR anomalies in the entire T range of investigation.