Crystal growth and stoichiometry-dependent properties of the ferromagnetic Weyl semimetal ZrCo_2-xSn

We report the growth of high quality bulk crystals, through crystallization from molten Sn flux, of the predicted ferromagnetic Weyl metal ZrCo_2-xSn with the L2₁ 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_2-xSn shows a significant change in minority and majority spin state occupancies and a shift in the Fermi level with Co deficiency.