Oxygen defects in langasite (La3Ga5SiO14) single crystal grown by vertical Bridgman (VB) method

Optical and scintillation properties of Ca3NbGa3Si2O14 single crystal grown by micro-pulling down method

“…and Qi et al reported that the crystal grown by Cz method was colorless and similar absorptions were not observed [14,15]. In the case of the crystal grown using the iridium crucible, the absorption around 350 nm was known to be observed [4,11,12]. In contrast, Pt-Ru crucible was used in our study.…”

“…Furthermore, Zhang et al and Taishi et al reported that absorption around 500 nm and a piezoelectric characteristic were changed by annealing [10,11]. On the other hand, there is report that the absorption from 285 to 500 nm for the langasite-type single crystal is related with the structure lattice defects [12].…”

Characterization of high temperature piezoelectric crystals with an ordered langasite structure

“…11 Thus, numerous studies have been carried out, in order to increase the resistivity ͑decrease conductivity͒, such as growing and annealing LGS crystals in an argon ͑Ar͒ atmosphere, minimizing the Ir crucible contamination during growth and compositional modification including strontium or aluminum. [11][12][13][14][15] LGS crystals belong to the trigonal system ͑point group 32͒, with the general formula of A 3 BC 3 D 2 O 14 . Here, A and B represent a decahedral ͑twisted Thomson cube͒ sites coordinated by eight oxygens and an octahedral site coordinated by six oxygens, respectively.…”

Luminescence of Eu-doped langanite nanopowders synthesized by a citrate sol–gel method

“…the reddish coloration of the samples is intensified with the annealing temperature). The red coloration of the crystals from the langasite family is related to point defects involving oxygen [14][15][16].…”