Crystal growth and stoichiometry-dependent properties of the ferromagnetic Weyl semimetal ZrCo Sn.

We report the growth of high quality bulk crystals, through crystallization from molten Sn flux, of the predicted ferromagnetic Weyl metal ZrCo Sn with the L2 Heusler phase structure. The concentration of Co vacancies in the single crystals is found to be dependent on the initial concentration of Co in the flux. The saturation magnetization increases approximately linearly with decreasing Co deficiency and the ferromagnetic transition temperature changes significantly. p-type carrier conduction and an anomalous Hall effect are observed. The calculated electronic density of states of ZrCo Sn shows a significant change in minority and majority spin state occupancies and a shift in the Fermi level with Co deficiency.