RF penetration depth in superconducting upt 3 with double heat capacity anomaly

Abstract

The radiofrequency penetration depth has been measured in a polycrystalline sample of UPt 3 that has been observed to have a double-peak structure in the specific heat. At low temperatures, the penetration depth va ries as T 4, consistent with similar measurements on single crystals. No change in the penetration depth, or its variation with temperature, is detected at the onset of the lower transition.