Polarized Crystal Spectra of CoF2 and Co0.06Zn0.94F2

Polarized spectra of oriented single‐crystal CoF₂ and Co_0.06Zn_0.94F₂ are presented in the range 5000–25 000 cm⁻¹ at 298, 77, and 20.4°K. Molar extinction coefficients and oscillator strengths are calculated. The spectra of CoF₂ and of dilute Co²⁺ in ZnF₂ are very similar. The principal bands are identified as transitions from the ${}^4{T}_{\text{1g}}{(}^4\mathrm{F)}$ ground level to ${}^4{T}_{\text{2g}}{(}^4\mathrm{F)}$ , ${}^4{A}_{\text{2g}}{(}^4\mathrm{F)}$ , and ${}^4{T}_{\text{1g}}{(}^4\mathrm{P)}$ levels. A value of $\text{Dq\hspace{0.17em}=\hspace{0.17em}715}{\mathrm{cm}}^{\text{−1}}$ is obtained. A sharp electric dipole line, 10 cm⁻¹ wide, is seen at 22 768 cm⁻¹ in CoF₂ at 20.4°K.