Mossbauer isomer shifts in rare earth compounds. I. General trends

Abstract

Mossbauer-effect isomer shift measurement on seven different rare earths are compared to show the strong correlation which exists between isomorphous compounds or alloys of the 4f series. The comparison shows that the rare earth trifluoride represents a very good approximation to an ionic salt for isomer shift purposes. The isomer shifts of the divalent alloys of europium are shown to correlate very well with those of trivalent alloys of the other rare earths and the 'core' for europium in the metallic state is shown to be very different from a 4f7 configuration.