Influence of high pressure and magnetic Fields on the magnetic and transport anomalies in Nd₇Rh₃

Abstract

The compound, Nd₇Rh₃, has been recently shown by us to exhibit exceptional magnetic and transport behavior. There are at least two antiferromagnetic transitions as a function of temperature (10 and 32 K) with the 10 K-transition being first-order-like at low fields; in addition, there is a field-induced first-order (metamagnetic) transition at temperatures well below 10 K. We have investigated the influence of external pressure (<15 kbar) on the magnetic and transport anomalies for this compound. We find that the two transition temperatures interestingly vary in opposite directions with increasing pressure and that the external pressure suppresses the critical field required to induce the metamagnetic magnetism. External pressure, while retaining (magnetic) phase co-existence phenomenon and percolative electrical conduction after field cycling (similar to the behavior known for by-now well-known manganites), suppresses the magnitude of magnetoresistance at high fields. We also report heat-capacity data in the presence of magnetic fields and it appears that the linear term decreases in the presence of a magnetic field as though there is a band splitting effect.