Title :
Upper critical field of borocarbide superconductors
Author :
Lan, M.D. ; Chang, J.C. ; Lu, K.T. ; Lee, C.Y. ; Shih, H.Y. ; Jeng, G.Y.
Author_Institution :
Dept. of Phys., Nat. Chung-Hsing Univ., Taichung, Taiwan
fDate :
3/1/2001 12:00:00 AM
Abstract :
We have investigated the upper critical fields of Y1-xErxNi2B2C and Y1-x ErxPd5B3C0.4 (0⩽x⩽1) systems by the scaling analysis of the thermal fluctuation conductivity. The experiments were done over wide magnetic field range. We are going to test the thermal fluctuation theory in the borocarbide superconducting systems. According to the scaling analysis, the thermal fluctuation conductivity should be scaled as σf =((T2)/H)(1/3)F[A(T-Tc(H))/((TH)(2/3))]. Because the scaling function is field independent, all scaling curves obtained under various applied fields should converge to a universal curve if the function of T c(H) is properly chosen, We therefore obtain Hc2(T) determined by optimizing the scaling fit. The superconducting coherence length and Ginzburg-Landau parameter K in those superconductors are also estimated. We categorize the Y1-x ErxNi2B2C and Y1-xEr xPd5B3C0.4 systems as strong type-II superconductors
Keywords :
Ginzburg-Landau theory; coherence length; erbium compounds; fluctuations in superconductors; magnetoresistance; nickel compounds; palladium compounds; superconducting critical field; type II superconductors; yttrium compounds; Ginzburg-Landau parameter; YErNi2B2C; YErPd5B3C0.4; borocarbide superconductors; coherence length; scaling analysis; strong type-II superconductors; thermal fluctuation conductivity; upper critical fields; Fluctuations; Magnetic analysis; Magnetic field measurement; Magnetic fields; Magnetoresistance; Superconducting materials; Superconducting transition temperature; Superconductivity; System testing; Thermal conductivity;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
