Large magnetoresistance anomalies in Dy7Rh3

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