Gallium phosphate

Gallium phosphate
Names
Other names
Gallium monophosphate
Phosphoric acid, gallium salt (1:1)
Gallium orthophosphate
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/Ga.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+3;/p-3
    Key: LWFNJDOYCSNXDO-UHFFFAOYSA-K
  • O=P12O[Ga](O1)O2
  • [Ga+3].[O-]P([O-])([O-])=O
Properties
GaPO4
Molar mass 164.694 g/mol
Appearance Transparent crystals
Insoluble
no=1.605, ne=1.623
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
GaPO4
General
Category crystal
Chemical formula (or Composition) GaPO4
Identification
Color Clear
Crystal system Trigonal
Crystal class 32 or D3 (Schönflies)
Cleavage None
Fracture Conchoidal
Mohs Scale hardness 5.5
Refractive index no=1.605, ne=1.623
Pleochroism None
Streak White
Density 3570 kg/m3
Solubility insoluble in pH = 5 - 8
other properties
Pyroelectricity None
Particular characteristics quartz isotype, piezoelectric effect up to 950°C (1742°F)

Gallium phosphate (GaPO4 or gallium orthophosphate) is a colorless trigonal crystal with a hardness of 5.5 on the Mohs scale. GaPO4 is isotypic with quartz, possessing very similar properties, but the silicon atoms are alternately substituted with gallium and phosphorus, thereby doubling the piezoelectric effect. GaPO4 has many advantages over quartz for technical applications, like a higher electromechanical coupling coefficient in resonators, due to this doubling. Contrary to quartz, GaPO4 is not found in nature. Therefore, a hydrothermal process must be used to synthesize the crystal.