Infrared and raman spectroscopic study of (formula presented) materials grown by molecular-beam epitaxy

Molecular beam epitaxy and optical investigation of (Formula presented) epilayers over a large composition range (Formula presented) grown on GaAs (001) substrates, are reported. The far-infrared (FIR) reflectance and Raman scattering were performed to characterize the film quality and study their optical and electrical properties. FIR and Raman data provide experimental evidence on the intermediate-mode phonon behavior for (Formula presented) with x up to 0.78. Theoretical modeling fits of FIR spectra lead to the determination of optical parameters such as mode frequency, strength, damping constant, and electrical properties of dielectric constant, carrier concentration, mobility, conductivity, and effect mass, and their dependence on the Mn composition. Values of force constants of (Formula presented) and (Formula presented) and the high-frequency limit dielectric constant of MnSe, (Formula presented) are obtained.