Magnetic and transport properties of Zr1-x Nb x Co2Sn.

Abstract

ZrCo2Sn is a potential candidate as a Weyl semimetal with a ferromagnetic ground state, and Nb-doping is expected to shift the Weyl points to the vicinity of Fermi level. We successfully synthesized a series of Zr1-x Nb x Co2Sn single crystals with various concentrations of Nb (x\u2009\u2009=\u2009\u20090, 0.1, 0.2, 0.275, 0.4, 0.5). All samples have a spinel structure and the lattice constant decrease as the Nb doping level increases. The magnetization and transport measurements suggest that the ferromagnetic ordering temperature can be strongly modified by the Nb doping. When x increases, the Curie temperature decreases significantly, accompanied by a change from metal-like to semiconductor-like behavior. There is a crossover for positive to negative MR at a temperature between 30\u2009K to 50\u2009K. In constant, the magnitude of the anomalous Hall resistance increases monotonously with decreasing temperature.