Slow electronic relaxation in the paramagnetic phase of Tm3Al2(magnetic and Mossbauer measurements)

Abstract

Magnetic and Mossbauer measurements have been made on the intermetallic compound Tm3Al2 from 1.3K to 45K. The susceptibility data show that this compound orders magnetically at 6K. The 169Tm Mossbauer spectra at 1.3K reveal a normal fully split six-line spectrum. At temperatures above 6K the spectra can be described in terms of two component sub-spectra. One sub-spectrum is characterised by a fully split six-line pattern whose total splitting and linewidth are virtually temperature independent, and a gradual decrease in its intensity as the temperature is raised. The other sub-spectrum exhibits typical paramagnetic relaxation behaviour leading to an absorption in the centre of the spectrum whose area increases as the temperature is raised. The presence of a fully split component at temperatures eight times higher than TN indicates an electronic Tm state with an unusually long relaxation time for a metallic material.