The Effects of Exchange Interactions in the Spectra of Octahedral Manganese. II. Compounds

Abstract

Earlier experimental work (J. Ferguson, H. J. Guggenheim and Y. Tanabe, J. appl. Phys. 36 (1965) 1046, Phys. Rev. Letters 14 (1965) 737) on the Mn pair spectrum of KZnF₃:Mn and the spectrum of KMnF₃ has been extended. The narrow bands of KMnF₃ and RbMnF₃ have been assigned and their abnormally high intensities established. The transition is an electric dipole one and oscillator strength (∼9.5×10⁻⁷ for the 4000 Å absorption) is temperature independent, corresponding to an allowed transition.
The experimentally observed features of the pair absorption suggest a possible form of interaction between radiation and paramagnetic ion pair. The origin of this interaction is discussed and an order of magnitude argument is given to support the proposed mechanism. Related problems such as exchange interaction in excited states and the spectra of the concentrated materials are also considered.