Large magnetoresistance in the magnetically ordered state as well as in the paramagnetic state near 300 K in an intermetallic compound, Gd₇Rh₃

Abstract

We report the response of electrical resistivity ρ to the application of magnetic fields (H) up to 140 kOe in the temperature interval 1.8-300 K for the compound Gd₇Rh₃, ordering antiferromagnetically below 150 K. We find that there is an unusually large decrease of ρ for moderate values of H in the close vicinity of room temperature, uncharacteristic of paramagnets, with the magnitude of the magnetoresistance increasing with decreasing temperature as though the spin-order contribution to ρ is temperature dependent. In addition, this compound exhibits giant-magnetoresistance behaviour at rather high temperatures (above 77 K) in the magnetically ordered state due to a metamagnetic transition.