Vortex phase diagrams in R3Rh4Sn13 (R = Yb, Ca)

A comparative study of vortex phase diagrams in two weakly pinned low T-c superconductors, Ca3Rh4Sn13 (CaRhSn) and Yb3Rh4Sn13 (YbRhSn), is presented. In CaRhSn, we can witness a disorder-driven transition via the phenomenon of second magnetization peak whose field-temperature dependence is analogous to that often discussed in the context of a Bragg glass (BG) to vortex glass (VG) transition. (C) 2002 Elsevier Science B.V. All rights reserved