STRUCTURAL, MAGNETIC, AND MAGNETOCALORIC PROPERTIES OF (HF0.83TA0.17)FE-2+X MATERIALS

We have investigated the sensitivity of structural, magnetic, and magn etocaloric properties of (Hf0.83Ta0.17)Fe-2+x alloys (x=-0.18, -0.09, -0.02, 0.00, 0.09, 0.26) to Fe content. As-cast samples for all x cons ist essentially exclusively of hexagonal MgZn2-type material. Via magn etization and differential scanning calorimetry measurements we find t hat all the alloys except x=0.26 feature both a ferromagnetic-->antife rromagnetic (FM-->AFM) transition at temperature T-0 and a Neel transi tion. The most abrupt FM-->AFM transition occurs in the x=-0.02 materi al which also exhibits the lowest T-0 and largest low-temperature mome nt. We report a magnetocaloric property the field-induced entropy chan ge Delta S, for the x=0.00 and x=+/-0.09 alloys. (C) 1996 American Ins titute of Physics.