Orbitally Nondegenerate Iron(III) Dithiocarbamates. I. Mouml;ssbauer Relaxation Phenomena

摘要

Mouml;ssbauer investigations of (i) bis(N,Nhyphen;diisopropyldithiocarbamato) iron (III) chloride, (ii) bis, (NNhyphen;diethyldithiocarbamato) iron (III) bromide, (iii) iron (III) trispyrrolidinedithiocarbamate, and (iv) bis(NNhyphen;diethyldithiocarbamato) iron (III) chloride are discussed. Compounds (i)ndash;(iii) are paramagnetic. Their Mouml;ssbauer spectra show the presence of ldquo;nonadiabaticrdquo; relaxation effects which require for their interpretation the recent theories of Blume and Tjon, or Gabriel. For these compounds a single phenomenological relaxation rate constantC, representing electronic relaxation, was sufficient to characterize the temperaturehyphen;dependent features in the spectra. The approximation of a single relaxation rateCis rigorously valid only in a polarized sample. The error involved in use of the method in paramagnetic samples is estimated from experiments in ferromagnetic compound (iv), where the value ofCconsistent with data for temperatures belowTC(2.43deg;K) was found to be roughly onehyphen;third of the relaxation rate derived from data at higher temperatures.