Multiphonon Raman Scattering in Coupled Cd1–xMnxS Nanoparticles: Magnetic Doping and Thermal Annealing

Abstract

We report on multiphonon Raman scattering in coupled Cd1–xMnxS nanoparticles grown within a glass matrix by the melting nucleation approach. Magnetic force microscopy identified two different-sized groups of nanoparticles coupled together. The high-frequency shoulder appearing above the longitudinal optical (LO) phonon mode has evidenced the acoustic–optical phonon coupling in nanoparticles, which depends upon the Mn doping. We found that the multiphonon Raman scattering and the electron–LO phonon coupling can be tuned by thermal annealing. Finally, we found that the magnetic doping induces changes on both the sp–d exchange interaction and the nanoparticles’ crystalline quality. We emphasize that our findings may have an impact on possible technological applications that request handling of the optically induced nonlinear features in nanoparticles which are favored by electron–phonon anharmonicities.