Electron Spin Resonance of Fe3+-Associated Centers in Cadmium Selenide

Abstract

Electron spin resonance of a Fe 3+ -associated center in cadmium selenide has been observed at liquid helium temperatures. The center responsible for the resonance has been identified as being a Fe 3+ ion occupying a cadmium site that is associated with a negatively charged defect on one of the six cadmium sites nearest to the Fe 3+ ion. The spin Hamiltonian for a Fe 3+ center of orthorhombic symmetry having S =5/2 is \(\mathscr{H}{=}g_{0}\beta\textbf{\itshape H}.\textbf{\itshape S}+D{S_{z}}^{2}+E({S_{x}}^{2}-{S_{y}}^{2})\), where the y -axis is rotated 16.5° away from the c -axis toward the line connecting a Fe 3+ ion with one of the six cadmium site nearest Fe 3+ and the x -axis lies in the (11\bar20) plane containing the y -axis. The effective g -values for the transition within the lowest Kramers doublet are given by g x =0.91±0.02, g y =9.24±0.06, and g z =1.68±0.03. The intensity variation of the resonance signal with irradiation of light of various wavelengths has been measured and can be interpret...