A.B. McLean, R.H. Williams
Journal of Physics C: Solid State Physics
We have observed inter-term Raman scattering from 5T2g→5Eg Frenkel excitons in antiferromagnetic FeF2. It differs qualitatively from previously observed intra-term scattering in a sharply reduced zero-phonon cross section and the appearance of relatively strong exciton-phonon scattering. Since the Raman process is fully allowed, it is possible to measure excited state Debye-Waller factors, D, and we find D(Λ3+ + Λ4+, 5Eg) = 0.04 and D(Λ1+, 5Eg) = 0.03. © 1974.