Phase transition of LaAlO3 nanocrystal enhanced optical linear& third order nonlinear and dielectric properties of glasses

Abstract

The third-order nonlinearity is an important and widely used optical property in optoelectronic devices. In this study, the phase transition of LaAlO3 in glass and the same influence on glass structure, optical linear& nonlinear, and electric properties were investigated through various techniques such as nuclear magnetic resonance, Transmission electron microscopy, X-ray photoelectron microscopy, etc. The phase transition from cubic to distorted rhombohedral LaAlO3 was verified and computer simulation based on density functional theory. Phase transition yielded TeO4→TeO3, AlO6→AlO4, and BO4→BO3 conversion and non-bridging oxygen in the glass network. Such modifications greatly red-shifted the absorption edge and enhanced the nonlinear susceptibility x(3), refractive index, and electric conductivity σ as well. The 10%LAO glass exhibited giant x(3) = 9.26×10−7 esu and σ= 9.22×10−8 Ω/cm which is 3-folds and 9-folds to that of the host glass, respectively. The obtained value was superior to works of literature and is promising for nonlinear photonics applications.