Title :
A new class of ordered langasite structure compounds
Author :
Chai, B.H.T. ; Bustamante, A.N.P. ; Chou, M.C.
Author_Institution :
Crystal Photonics Inc., Sanford, FL, USA
Abstract :
Langasite (LGS) and its isomorphs are only a few piezoelectric crystals which have the unique temperature compensation property. But most of the known langasite structure compounds are disordered. Disorder causes higher acoustic losses and also nonuniform mechanical properties. We reported a new class of langasite isomorph which has all the cations totally ordered. They are CNGS (Ca3NbGa3Si2 O14), CTGS (Ca3TaGa3Si2O14), SNGS (Sr 3NbGa3Si2O14) and STGS (Sr 3TaGa3Si2O14). They all melt congruently. High quality single crystals were produced by Czochralski melt pulling technique. They have the advantages of low Ga2O 3 content, high acoustic velocity and low acoustic loss
Keywords :
calcium compounds; crystal growth from melt; crystal structure; gallium compounds; isomorphism; lattice constants; niobium compounds; piezoelectric materials; strontium compounds; surface acoustic waves; tantalum compounds; Ca3NbGa3Si2O14; Ca3TaGa3Si2O14; Czochralski melt pulling technique; SAW velocity; Sr3NbGa3Si2O14; Sr3TaGa3Si2O14; crystal structure; high acoustic velocity; high quality single crystals; langasite isomorphs; lattice constants; low Ga2O3 content; low acoustic loss; ordered langasite structure compounds; piezoelectric crystals; temperature compensation property; totally ordered cations; Acoustic materials; Acoustic waves; Chemicals; Crystalline materials; Gallium arsenide; Material properties; Mechanical factors; Photonic crystals; Surface acoustic waves; Temperature;
Conference_Titel :
Frequency Control Symposium and Exhibition, 2000. Proceedings of the 2000 IEEE/EIA International
Conference_Location :
Kansas City, MO
Print_ISBN :
0-7803-5838-4
DOI :
10.1109/FREQ.2000.887346
