Defects related to oxygen and other impurities in piezoelectric langasite (La3Ga5SiO14; LGS) single crystals grown by the vertical Bridgman (VB) method was investigated. The resistivity of an LGS crystal grown in an Ar atmosphere was about one-order higher than that grown in air. However, after annealing in air it decreased to the same level as that of LGS crystal grown in air. The results of optical transmission spectra showed a broad adsorption peak around 500 nm, corresponding to 2.5 eV of energy level, in LGS crystals grown in air and grown in an Ar atmosphere. Since VB-grown LGS crystal was p-type, excess interstitial oxygen atoms, not oxygen vacancies, operate as an acceptor in the VB-LGS crystal.
- Langasite single crystal
- Oxygen defects
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering