SYSTEMATICS OF THE RAG PHASES

The systematic trends of the properties of the RAg compounds have been examined. The anomalous properties of EuAg and YbAg, which are due to the divalent nature of Eu and Yb, are quite evident. The use of syste matics to estimate the melting points of PmAg, TmAg and LuAg are discu ssed, and so is the anomalous low melting point of SmAg relative to it s neighboring lanthanides. The relative volume ratio technique to esti mate the free energy (heat) of formation trend in the RAg compounds ma y not be too useful since there is considerable scatter in the data. T he melting point trend indicates that 4fbonding occurs in the light la nthanide, but not in the heavy lanthanide RAg phases.