Impact of growth atmosphere on langatate (La3Ga5.5Ta0·5O14) crystals grown by czochralski technique and its coloration

Growth of high-quality langatate crystals by the Czochralski method with elimination of Ga2O3 volatilization

“…However, defects like cracks, inclusions and polycrystals easily occur when growing LGT crystals from the stoichiometric composition. 11 Three phases, LaGaO 3 , LaTaO 4 , and Ga 2 O 3 are reported to coexist with LGT, and Ga 2 O 3 is easily decomposed during the heating step under a low oxygen content atmosphere. 12 The evaporation of Ga 2 O 3 disrupts the mass transport from hot to cold zones during the growth process, inhibiting the preparation of high-quality large-size LGT.…”

“…13 In 2022, B. Boutahraoui et al grew LGT crystals with a diameter of 50 mm under the Ar (0.1–1% O 2 ) gas mixture atmosphere; the crystals show great optical properties and the resistivity is sensitive to the growth atmosphere. 11 However, attributed to the oxidation of Ir crucible, it is hard to grow LGT crystals in a gas atmosphere with high content of O 2 by the traditional Cz method, thereby limiting further improvement in the quality of LGT crystals.…”

Highlights on the reversible nonpolar-to-polar P3121–P31 phase transition at low temperature in NaLa(SO4)2·H2O: mechanism and piezoelectric properties

“…9,14 Langatate or langasite are compounds with the A 3 BC 3 D 2 O 14 general formula and adopt the P321 space group. 15 They can be described as a framework formed by five tetrahedra (three CO 4 and two DO 4 ), one BO 6 octahedron, and A is a decahedral site coordinated by eight oxygen atoms. In particular, the La 3 Ga 5 SiO 14 langasite has a piezoelectricstrain constant (d 11 B À6.5 pC N À1 ) 16 2.5 times higher than in a-quartz, an electromechanical coupling coefficient of k 26 = 13.4% 17 and no structural phase transition between room temperature and its melting point at 1470 1C.…”