Vibrational Structure in the Fluorescence Spectrum ofEu3+in KTaO3

Vibrational satellite structure has been observed in the fluorescence spectrum of ${\mathrm{Eu}}^{3+}$ in the cubic perovskite KTa${\mathrm{O}}_3$. A comparison is made between the frequencies of vibrational peaks associated with the ${}_{}{}^5{}_{}{}^{}D_0^{}{}_{}{}^{}\to {}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$ zero-phonon line at 77°K and observed or predicted lattice vibrational frequencies of KTa${\mathrm{O}}_3$. The ${}_{}{}^5{}_{}{}^{}D_0^{}{}_{}{}^{}\to {}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$, ${}_{}{}^7{}_{}{}^{}F_2^{}{}_{}{}^{}$ regions of the fluorescence spectra of ${\mathrm{Eu}}^{3+}$ in KTa${\mathrm{O}}_3$ and SrTi${\mathrm{O}}_3$ at 77°K are also compared and discussed. The frequencies and structure of the satellite fluorescence spectra of ${\mathrm{Eu}}^{3+}$ in the two lattices are different.