Effect of Nonmagnetic Ion Lu Substitution for Dy on Superconductivity and Magnetism in Antiferromagnetic Superconductor Dy_{1x}Lu_{x}Ni_{2}B_{2}C Compound
Abstract
A series of Dy_{1x}Lu_{x}Ni_{2}B_{2}C (x=01) compounds have been investigated by Xray diffraction and by examining the temperature dependences of electrical resistivity, magnetization and heat capacity. All the samples exhibit the same LuNi_{2}B_{2}Ctype structure; and lattice parameters depend almost linearly on the Lu concentration x. The superconducting transition temperature T_{c} decreases rapidly with increasing x, and superconductivity disappears at approximately x=0.2, then increases with a further increase in x. The magnetic transition temperature T_{M} and the effective magnetic moment P_{eff} decrease gradually with increasing x. The ferrimagneticlike behavior emerges at about x=0.2; which can be the main reason causing the suppression of superconductivity. The temperature dependence of the magnetic entropy S_{m} originated from Dy ions has been evaluated on the basis of heat capacity data. The saturated values of S_{m}(T)/(1x) are approximately 90% of R\ln 4 and the effective magnetic moment normalized by Dy concentration is almost unchanged, which indicates that the magnetic ground state of Dy^{3+} does not show a pronounced change.
 Publication:

Japanese Journal of Applied Physics
 Pub Date:
 October 2007
 DOI:
 10.1143/JJAP.46.6604
 Bibcode:
 2007JaJAP..46.6604L