Single crystal epr studies on one-dimensional α: Form of bis(N-methyl salicylaldiminato)copper(II) in the temperature interval 10–290 K

Abstract

Abstract Present studies have revealed that one-dimensional (1D) spin dynamics of α:bis(N-methyl salicylaldiminato)copper(II) is retained down to 10K. Linewidth anisotropy in crystallographic ac and ab planes has been satisfactorily explained on the basis of the anisotropic exchange theory of McGregor and Soos. The fitted value of the anisotropic exchange parameter is of the same order of magnitude as that derived from the well known Moriya relation. It is shown that the crystal has excellent 1D magnetic dimensionality. The linewidth vs temperature curve along the chain axis shows discontinuities at ~ 240 K and ~ 50 K. The first discontinuity is consistent with that observed from powder X-ray data. The logarithm of signal intensity vs temperature curve consists of three linear portions having different slopes with discontinuities at ~ 180 K and ~ 50 K. The former temperature corresponds to the transition point obtained from single crystal X-ray measurements. The discontinuity at ~ 50 K is suggestive of a second transition in the crystal. The observed thermal behaviour of the EPR line intensity appears to be a special feature of the present 1D Cu(II) system.