title: Generalized Pseudo-Unit-Cell model for long-wavelength optical phonons of multinary mixed crystals: application to A(x)B(1-x)C(y)D(1-y) type mixed crystals.
abstract: Long-wavelength optical phonons in multinary mixed crystals are studied based on the Pseudo-Unit-Cell model. A unitary matrix method is developed to calculate the eigenfrequencies of optical phonons in multinary mixed crystals. The analytical expressions of oscillator strengths and dielectric constants of the multinary mixed crystals are obtained as a function of the phonon frequencies. The results indicate that the composition dependence of oscillator strengths shows clearly the phonon-mode behaviors of the mixed crystals. The theory and calculation method can be applied to any type of multinary mixed crystals. It is found that there is a composition independent point for the dielectric constant of quaternary mixed crystals.
authors.affiliation: Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060, China.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Liao
authors.forename: Jingzhen
authors.initials: J
authors.lastname: Li
authors.forename: Ruisheng
authors.initials: R
authors.lastname: Zheng
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Lu
authors.forename: Hongyi
authors.initials: H
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D003460:Crystallization; D008027:Light; D008420:Manufactured Materials; D008962:Models, Theoretical; D017785:Photons; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*