Observation of a minimum in the temperature-dependent electrical resistance above the magnetic-ordering temperature in Gd 2 PdSi 3

Results on electrical resistivity, magnetoresistance, magnetic susceptibility, heat capacity and 155 Gd Mössbauer measurements on a Gd-based intermetallic compound, Gd 2 PdSi 3 , are reported. A finding of interest is that the resistivity unexpectedly shows a well-defined minimum at about 45 K, well above the long-range magnetic-ordering temperature (21 K), a feature which gets suppressed by the application of a magnetic field. This observation in a Gd alloy presents an interesting scenario. On the basis of our results, we propose electron localization induced by s - f (or d - f ) exchange interaction prior to long-range magnetic order as a mechanism for the electrical resistance minimum.