Ultraviolet Absorption Spectra of MNF2, KMNF3, RBMNF3, and CSMNF3

摘要

Absorption spectra in the 3000-4000 A region are presented for MnF2, KMnF3, RbMnF3, and CsMnF3 at room temperature, liquid air temperature, and liquid helium temperature. The spectra are similar at room temperature, but marked differences appear at low temperatures due to the occurrence of an antiferromagnetic phase transition. The spectra are classified, and calculations of the positions of the room temperature lines are given in terms of a modification of ligand field theory. Values of the crystal field splitting and of a covalency parameter are given for the four crystals. Some classification of the low temperature lines is made in terms of the phenomena causing their occurrence. (Author)