Raman-scattering study of KxSr1-xFe2As2 (x=0.0, 0.4)

Polarized Raman spectra of nonsuperconducting SrFe(2)As(2) and superconducting K(0.4)Sr(0.6)Fe(2)As(2) (T(c)=37 K) microcrystals are reported. All four-phonon modes (A(1g)+B(1g)+2E(g)) allowed by symmetry are found and identified. Shell model gives reasonable description of the spectra. No detectable anomalies are observed near the tetragonal-to-orthorhombic transition in SrFe(2)As(2) or the superconducting transition in K(0.4)Sr(0.6)Fe(2)As(2).