Solid-state grain growth of garnet single crystals of complex composition

Abstract

Various (Nd-doped (Y,Gd,La,Lu)3(Sc,Al)5O12) garnets were reproducibly grown from a Nd-doped (Y,Gd,La,Lu)3(Sc,Al)5O12 polycrystalline precursor. Single crystals were grown through controlled abnormal grain growth at temperatures between 1750°C and 1850°C. Nd-doped (Y,Gd,La,Lu)3(Sc,Al)5O12 powder was prepared using the co-precipitation method, and single crystals were fabricated by the conversion of polycrystalline material. The phase identification of the specimens was performed using XRD and X-ray double crystal rocking curve (DCRC) analysis. The absorption spectra, fluorescence spectra, and fluorescence lifetimes of samples excited using an 808nm laser diode (LD) were also measured. The fluorescence lifetime of Nd-doped (Y,Gd,La,Lu)3(Sc,Al)5O12 single crystals is longer than that of Nd:YAG; a prolonged fluorescence lifetime helps to achieve a high laser output power. In short, we can fabricate complex mixed-garnet single crystals using the solid-state single-crystal conversion (SCC) method.