2007/05/31 by M. E. McBriarty, P. Kumar, McBriarty, M. E. +5
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.0705.4659
arxiv created 2007/05/31 · arxiv updated 2009/12/01
Specific heat, dc- and ac-magnetic susceptibility are reported for a large single crystal of PrOs4Sb12 and, after grinding, its powder. The room temperature effective paramagnetic moment of the crystal was consistent with the Pr3+ ionic configuration and full occupancy of the Pr-sublattice. The crystal showed two distinct anomalies in the specific heat and an overall discontinuity in C/T of more than 1000 mJ/K2mol. The upper transition (at Tc1) was rounded, in an agreement with previous reports. The anomaly at Tc2 was very sharp, consistent with a good quality of the crystal. We observed a shoulder in χ' and two peaks in χ'' below Tc1. However, there were no signatures in χ' of the lower temperature transition. PrOs4Sb12 is extremely sensitive to grinding, which suppresses the upper superconducting transition in both the specific heat and magnetic susceptibility. ΔC/Tc was reduced to 140 mJ/K2 mol in the powdered sample. Existing data on ground, polished, and sliced crystals suggests the existence of a length scale of order 100 μ, characterizing the higher temperature superconducting phase.