ELECTRONIC RELAXATION IN RARE EARTH METALS AND ALLOYS - A NON-KRAMERS EXAMPLE : Tm³⁺

Rare Earth Mössbauer Spectroscopy Measurements on Lanthanide Intermetallics

“…It seems that in this temperature range the quadrupolar pair interaction is not strong enough to align the Tm moments, as shown by Jaussaud et al (1980). Dixon et al (1980) found the same parameters for the hyperfine field and the electric splitting at T ¼ 65 mK. Moreover, they found in the central part an additional single line, which is not present above.…”

“…The orthorhombic compound TmAl orders at T N ¼ 11 K as found by Dixon et al (1980). Above T N at least up to 60 K slow relaxation was observed.…”

“…x Al y compounds In three Tm x Al y compounds, Tm 2 Al, Tm 3 Al 2 and TmAl, above their respective magnetic ordering temperatures slow magnetic relaxation is found by Bowden et al (1981Bowden et al ( , 1988 and Dixon et al (1980). Although Tm 2 Al (orthorhombic Ni 2 Si structure) shows slow magnetic relaxation as found by Bowden et al (1988), no magnetic order has been found down to T ¼ 1.4 K. Two fully split 169 Tm Mössbauer spectra were observed at 1.4 K, with two different hyperfine fields and electric quadrupole splittings corresponding to the two crystallographically different Tm sites.…”

“…Uhrich and Barnes (1967) have determined the lowest crystal field parameter B 2 0 ¼0.53 K from electric quadrupole splitting measurements above T N ¼ 56 K. Cohen (1968) has interpreted the 169 Tm spectra of Tm metal with an incommensurate magnetic structure supposing a fast relaxation limit. In contrast, Dixon et al (1980) has interpreted these spectra of Tm metal by including electronic relaxation using the matrix formalism of Hirst et al (1969). Dy metal has been studied by Bowden et al (1978) with 161 Dy Mössbauer spectroscopy.…”

Introduction à la relaxation électronique dans les solides : mécanismes et techniques de mesure

“…Signalons également quelques travaux sur la relaxation spin-spin de l'ion non-de Kramers Tm3 + [86,87] ; ces résultats cependant se prêtent difficilement à l'interprétation, à cause de la complexité de la structure de champ cristallin de Tm3+ (J = 6, donc 13 niveaux).…”