Crystal structure, magnetic and thermal properties of the non-stoichiometric alloys Tb0.95Pd2.20Mn0.85 and Dy1.00Pd2.15Mn0.85

The alloys RNi2Mn and RCo2Mn with R representing the rare earth element are isostructural analogues of the binary Laves phases RNi2, RCo2.We have synthesized the isoelectronic Pd-based RPd2Mn analogues with R = Gd, Tb, and Dy, for the first time.They crystallize in a cubic structure, however, not in the cubic C15 (Fd-3m) structure of RNi2Mn, nor the Laves phase' structure.Instead, the crystal lattice is described by the Im-3m space group with Tb/Dy, Pd, and Mn atoms randomly distributed over the 2a Wyckoff position of the W-type structure (A2, disordered bcc).The magnetization data reveal a standard paramagnetic behavior, with effective magnetic moments strikingly close to those expected for Tb 3+ and Dy 3+ free ions, down to 130 K. K e y w o r d s: RETM2Mn, RE1-yPd2+x+yMn1-x alloys, solid solutions,