MAGNETIC GRUNEISEN PARAMETERS IN FERROMAGNETIC FE65(NI1-XMNX)35 ALLOYS

The magnetic Gruneisen parameters, GAMMA(FM) and GAMMA(SF), are estimated by comparing the temperature dependence of the magnetic contributions to the thermal expansion and the bulk modulus, above and below the Curie temperature T(C), respectively, for samples having x = 0, 4, and 13 at. % Mn, in the alloy system Fe65(Ni1-xMnx)35. These are compared with the corresponding parameters GAMMA(0), obtained from the magnetovolume and the magnetic contribution to the bulk modulus at zero temperature, and GAMMA(C), obtained from the pressure dependence of T(C).