Polarization, temperature dependence and absorption mechanism of the electronic transitions in some linear antiferromagnets

Abstract

The polarized spectra of the linear chain complexes CsMnCl₃,2H₂O, CsMnBr₃,2H₂O and N(CH₃)₄MnCl₃ are measured over the temperature range 4.2–300 K. The mechanism of light absorption is predominantly exchange-induced electric dipole. The gross polarisations can be explained using the model of exchange-coupled pairs of metal ions but some of the fine structure is not understood. The temperature dependence of the band intensities follows qualitatively the predicted behaviour of Tanabe and Ebara's classical model.