Seed crystals

Abstract: a-quartz is mainly used for high frequencies devices, due to its piezoelectric properties. The development of higher frequencies than before for many applications leads to new requirements concel-ning the material (lowest concentsation of physico-chemical and structural defects) and consequently to its ctystal-growth. a-quartz, due to its piezoelectsic properties has led to the development of either industrial devices and consumer equipments [ I] (Table). Main Piezoelectric Applications of a-quartz Crystal (from Taki) Industrial equipment Consumer equipment The a-+ P transition taking place close to.573OC, the synthesis of a-quartz single clystals requires a low-temperature crystal-growth process. This condition has led to the development of the hydrothesmal process (Fig.). Radiocommunication, cable communication, electronic applications, measurement equipment, pager, security system (alarm)... Electronic handy calculator, watch clock, timer, cable TV, color TV, video recorder, RF converter, tranceiver, radio equipment, microphone, electronic appliance, microphone, electronic appliance, microcomputer and computer terminal, TV-game machine, telephone, copy machine... Article published online by EDP Sciences and available a