Electron-spin-resonance study of manganese-doped spinel

An electron-spin-resonance study of manganese-doped synthetic spinel samples (MgAl₂{O}₄$) produced spectra with six sharp main lines corresponding to the hyperfine components of the ${M}ₛ=1/2{↔}{M}ₛ={-}1/2$ transitions with the coupling constant $A=83$ G, ten sharp forbidden transitions, and a broad background arising from the effect of the $D$ tensor on the other four ${M}ₛ{↔}M_{}^{{'}}{}ₛ{}^{}$ transitions. The measured value of ${D}ₑₓₚₜ$ equal to 64 G was explained in terms of the Goodenough model using the Orbach et al. method.