An anomalous magnetic phase transition at 10 K in Nd7Rh3

TL;DR

This study investigates the magnetic and electronic properties of Nd7Rh3, revealing an unusual first-order magnetic phase transition at 10 K characterized by magnetic phase coexistence and significant magnetoresistance effects.

Contribution

The paper provides detailed experimental characterization of Nd7Rh3, identifying a novel first-order magnetic transition at 10 K and its associated electronic phenomena, expanding understanding of intermetallic magnetic phase behavior.

Findings

Sharp increase in magnetic susceptibility below 10 K in field-cooled measurements

Large negative magnetoresistance near the 10 K transition

Evidence of a first-order magnetic phase transition at 10 K

Abstract

The compound, Nd7Rh3, crystallizing in Th7Fe3-type hexagonal structure, has been shown recently by us to exhibit a signature of magnetic phase-coexistence phenomenon below 10 K after a field cycling, uncharacteristic of stoichiometric intermetallic compounds, bearing a relevance to the trends in the field of electronic phase-separation. In order to characterize this compound further, we have carried out dc magnetic susceptibility (chi), electrical resistivity, magnetoresistance and heat-capacity measurements as a function temperature (T= 1.8 to 300 K). The results reveal that this compound exhibits another unusual finding at the 10K-transition in the sense that the plot of chi(T) shows a sharp increase in the field-cooled cycle, whereas the zero-field-cooled curve shows a downturn below the transition. In addition, the sign of magnetoresistance is negative and the magnitude is large over a wide temperature range in the vicinity of magnetic ordering temperature, with a sharp variation at 10 K. The results indicate that the transition below 10 K is first-order in its character.