Abstract:
The macroscopic properties of the superconducting phase in the multiphase compound
YPd5B3 C.3 have been investigated. The onset of superconductivity was observed at 22.6
K, zero resistance at 21.2 K, the lower critical field Hel at 5 K was determined to be
Hel (5) rv 310 Gauss and the compound was found to be an extreme type-II superconductor
with the upper critical field in excess of 55000 Gauss at 15 K.
From the upper and lower critical field values obtained, several important parameters
of the superconducting state were determined at T = 15 K. The Ginzburg-Landau
paramater was determined to be ~ > 9 corresponding to a coherence length ~ rv 80A and
magnetic penetration depth of 800A.
In addition measurements of the superconducting transition temperature Te(P) under
purely hydrostatically applied pressure have been carried out. Te(P) of YPd5B3 C.3 decreases
linearly with dTe/dP rv -8.814 X 10-5 J</bar. The discussion of Te(P) will focus
on the influence pressure has on the phonon spectrum and the density of states near the
Fermi level.
