The polarized Raman spectra of (010)- and (001)-oriented epitaxial thin films of ${\mathrm{SrRuO}}_3$ (space group $Pnma,$ $Z=4\mathrm{}$) are measured between 5 and 300 K. The Raman lines at 123, 225, 252, 291, 361, 390–393, and $412{\mathrm{cm}}^{\mathrm{-}1}$ are assigned to definite modes of $A_g$ or $B_{2g}$ symmetry based of their polarization selection rules, the comparison with the results of lattice dynamical calculations (LDC), and accounting for the correlation between the Γ-point phonons in the $\mathrm{Pnma}$ structure and the Γ-, $R$-, $X$-, and $M$-point phonon modes in the parent $\mathrm{Pm}3\mathrm{}¯m$ structure. The pronounced anomalies of the Raman phonon parameters near the ferromagnetic transition ${(T}_c=148\mathrm{}\mathrm{K})$ are discussed in terms of enhanced spin-phonon coupling and reorganization of the electronic states in the vicinity of $T_c.$

• Received 21 May 1998

DOI:https://doi.org/10.1103/PhysRevB.59.364