Single crystal synthesis and properties of lithium-gallium-, lithium-aluminium-oxide and mixed compounds (I) growing of LiGaO2-, LiAlO2- and LiAlxGa1−x crystals from fluxes
✍ Scribed by Dr. H. Schwarzer; Prof. Dr. H. Neels
- Publisher
- John Wiley and Sons
- Year
- 1971
- Tongue
- English
- Weight
- 756 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0232-1300
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✦ Synopsis
LiGaO, forms a single eutectic with PbO/B,O, (molar ratio 9:4). A nearly linear slope of the liquidus curve is followed by a steep rise of the temperature coefficient of solubility. The solvent power a t 1300 "C is 0.35 g LiGaO,/g PbO, B,O,; from 1000 to 1300 "C there exist only poor differences in solubility of LiGaO, and LiA10, in PbO/B,O,. LiGaO, crystals up to 1 p in weight grew spontaneously by slow cooling from fluxes or by evaporation of the solvent, those of about 1 -1.5 p from seeds by cooling stirred fluxes. LiA10, crystals are essentially smaller ( 6 mm). -By partial substitution of Ga,O, by A1,0, mixed crystals LiAl,Gal-,O, result. I n the ease of 2 2 0.5 the coefficient of segregation remains 51. The A1 concentrations along the polar axis decrease by more than 2 5 P.c., perpendicular to [OOl] they keep constant till to tho crystal surface. -Crystals show hypermorphism' from mm2 t o mmm. With high initial exceedings only { 110) and {Oll}, with lower ones also { 120}, { 130), { 210) and { 310) as well as the reduced {loo), { 010) combinations are observed. -LiGaO, crystals grow by nucleous, sceletal or faceted growth resp. during the cooling period. -Primarily at 1270 "C formed nuclei up to 1150 "C grow to critical dimcnsions ( -0 . 5 mm) and develop to the main branch along [OOl]. Primary branches deflect to [OlO]. The convex secondary branches intergrow along (110), often including flux. With decreasing temperature a new crystallisation front is formed at the periphery leading to a stable faceted growth a t about 1000 "C.