Raman spectroscopy of highly aligned thin films of Sr 2 FeMoO 6

We report a comparative study of polarization‐resolved Raman spectra of highly aligned thin films of Sr 1.9 A 0.1 FeMoO 6 (A = Sr, Ca, Ba) and undoped bulk polycrystalline Sr 2 FeMoO 6 at room temperature. The films were fabricated by a non‐vacuum chemical deposition technique on LaAlO 3 substrates. A site group analysis was performed to establish that there are five A g and seven B g modes, most of which have been identified, and six E g modes, although the latter are not accessible in the c ‐axis aligned films. One B g mode shows clear evidence of an asymmetric lineshape, which is discussed in terms of an interaction between phonons and electronic excitations. Copyright © 2004 John Wiley & Sons, Ltd.