Electron energy loss spectroscopy studies of the amorphous to crystalline transition in FeF3

Electron beam-induced crystallization studies in amorphous FeF3 films using electron energy loss spectroscopy (EELS) are discussed in this letter. Tim e-resolved EELS studies show that the coordination polyhedra in amorphous F eF3 (a-FeF3) are randomly arranged FeF6 octahedra. They arrange themselves to give long range order during crystallization to FeF2 and FeF3 under the electron beam. Changes in the d-band occupancy by one electron as well as t he sensitivity of the ratio of the Fe L-3 and L-2 edges to the electronic c onfiguration of the iron ion are clearly seen during the crystallization pr ocess. (C) 1999 American Institute of Physics. [S0021-8979(99)03817-7].