Thermochemistry of Pd-In, Pd-Sn and Pd-Zn alloy systems

The standard enthalpy of formation of several Pd-M alloys (M = In, Sn and Zn) has been measured using a high temperature direct drop calorimeter. The reliability of the calorimetric results has been determined and supported by using different analytical techniques: light optical microscopy, scanning electron microscopy equipped with electron probe microanalysis (EPMA with EDS detector) and X-ray powder diffraction analysis. The values of Delta(f)H (kJ/inol atoms) for the following phases were obtained for the formation in the solid state at 300 K: PdIn (49 at.%In): -69.0 +/- 1.0; Pd(2)In(3) -57.0 +/- 1.0; Pd(3)In(7); -43.0 +/- 1.0; PdSn(2): -50.0 +/- 1.0; Pd(2)Zn(9) (77 at.%Zn): -33.7 +/- 1.0; Pd(2)Zn(9) (78 at.%Zn): -34.0 +/- 1.0; Pd(2)Zn(9) (80at.%Zn): -35.0 +/- 1.0. The results show exothermic values which increase from the Pd-Zn to the Pd-Sn and Pd-In systems: the data obtained have been discussed in comparison with those available in literature.