Gallium orthophosphate

Table 7.6 Material properties of gallium orthophosphate GaP04 (Krempl, Sehleinzer and Wallnofer (1997)) and berlinite AIPO4 (Bailey et al. 1982 Blistanov et al. 1982 Detaint et al. 1979)...

The principle of functionality of the EQCM is based on the fact that quartz, like some other materials (tourmaline, topaz, Rochelle salt, langasite, niobate, gallium-orthophosphate), is a piezoelectric material. Piezoelectricity was discovered in 1880 by the Curie brothers, Pierre and Jacques. It did not have the immediately impressive spread and use in the scientific community as other physical phenomena based on high frequency or on electromagnetic fields. However, in the USA, quartz crystal resonators were used in World War 1 in improving the ultrasonic submarine detectors [36]. 

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