Superconductivity and ferromagnetism in Pd doped Y9Co7

The ferromagnetic superconductor Y9Co7 was chemically doped to yield the solid solution Y9Co7-xPdx for 0 < x < 0.4. The lattice parameter a does not depend on x, whereas c increases with increasing Pd content up to x = 0.2, the palladium solubility limit. The transition from ferromagnetism (T-C = 4.25 K) to superconductivity (T-sc = 2.4 K) was observed only for the parent Y9Co7 compound. For the lowest tested Pd doping level (x = 0.05), ferromagnetism is enhanced strongly (T-C = 935 K) and superconductivity is not seen above 1.8 K. The Curie temperature rapidly increases from 4.25 K to about 10 K for a Pd concentration of x = 0.1 and remains almost unchanged for Y9Co6.8Pd0.2. (C) 2016 Elsevier Ltd. All rights reserved.