Thermochemistry of selected R-T-Al (R= rare earth, T= Ni, Pd) alloys

The synthesis, structure and properties of R-T-Al (R= rare earth, T= Ni and Pd) alloys are of growing interest for fundamental aspects as well as for potential applications in various technological fields, because of their typical properties. Selected R–T–Al ternary systems are considered in our laboratory in order to study different thermodynamic properties; in particular, results about the standard enthalpy of formation at 300K recently obtained for the RNiAl, RNi2Al3 and RPdAl will be presented. Experimental investigations have been performed by using direct calorimetry and different analytical techniques to check the state and composition of the samples: X−ray Powder Diffraction (XRD), Light Optical Microscopy (LOM), Scanning Electron Microscopy (SEM) and Electron Probe Micro-Analysis (EPMA). Results obtained for RNiAl, RNi2Al3 and RPdAl are discussed and compared also with those available for the binary compounds of the R-Ni and R-Pd systems.