Anomalous magnetoresistance near the metamagnetic transition in Gd2In

Gd2In, a layered intermetallic compound, displays two magnetic phase transitions below room temperature, the lower one being a metamagnetic transition occurring near 100 K. We have completed measurements of both zero-held resistivity for 1.5 less than or equal to T less than or equal to 300 K and the magnetoresistance in fields of up to 8 T for temperatures between 1.5 and 120 K; in addition the magnetization has been studied in fields up to 5.5 T in the temperature range 2 less than or equal to T less than or equal to 140 K. As the spin configuration in the ordered phases remains uncertain, these measurements concentrate on the behaviour near the 'ferromagnetic-to-antiferromagnetic' transition, and as such they can be compared and contrasted with those reported recently for Ru-doped CeFe2 in which the spin configurations are better known. Plots of the metamagnetic field as a function of temperature yield metamagnetic transition temperatures of between 94 and 96 K (in zero field), in good agreement with earlier estimates. Additional features are observed below 100 K in this system, suggesting differences between Gd2In and the doped CeFe2 system, originating possibly from fundamental differences in spin structure.