Abstract :
The piezoelectric, elastic, dielectric, thermal, optical, mechanical, chemical, surface acoustic wave (SAW) and bulk acoustic wave (BAW) coupling, and propagation properties of new piezoelectric-crystal lithium tetraborate Li2B4O7 (LBO) are reviewed. The growth and production of LBO crystal by the modified Bridgman (BR) technique (Fan´s process) and its application to SAW and BAW devices are also discussed. Attention is also given to such features of LBO growth as the critical requirement of stoichiometric purity for raw material, very low crystal growth rate, a convex or plane solid-liquid interface in the growth, a suitable procedure of self-annealing, and the practicality of the BR technique for commercialization of LBO material with a large diameter of 82 mm and high quality
Keywords :
bulk acoustic wave devices; crystal growth from melt; elastic constants; hardness; lithium compounds; permittivity; piezoelectric materials; surface acoustic wave devices; surface acoustic waves; thermal expansion; 82 mm; BAW coupling; BAW devices; Bridgman technique; Fan´s process; LBO crystal growth; Li2B4O7; SAW device; bulk acoustic wave; chemical properties; crystal growth rate; dielectric properties; elastic properties; mechanical properties; optical properties; piezoelectric properties; piezoelectric-crystal; propagation properties; self-annealing; solid-liquid interface; surface acoustic wave; thermal properties; Acoustic propagation; Acoustic waves; Chemicals; Dielectrics; Optical coupling; Optical propagation; Optical surface waves; Production; Raw materials; Surface acoustic waves;
