Synthesis and characterization of single crystalline Gd5(SixGe1−x)4 by the Bridgman method

Single crystals of Gd5(SixGe1−x)4 have been prepared by the Bridgman method using tungsten crucibles. The tungsten crucible was found to be chemically inert with respect to Gd, Si, Ge but did have limited solubility in liquid Gd5Si2Ge2, resulting in the precipitation of pure tungsten throughout the bulk crystal. Overall, the bulk crystal solidified in the monoclinic phase and a slight increase in Si content and decrease in Ge content at the growth proceeded was found. This increase in Si:Ge ratio resulted in a slight increase in lattice parameter of the monoclinic phase and an increase in the magnetostructural transformation temperature of ΔT = 10 K. AC susceptibility measurements indicated a small fraction of orthorhombic phase was present throughout the ingot which accounts for the decrease in MCE values along the length of the ingot.