Thermodynamic properties of gallium hydroxide oxide (α-GaOOH) at temperatures to 700 K

Dipeptide-assisted growth of uniform gallium oxohydroxide spindles

“…1(d)) where the d-spacing of the lattice fringe was 2.97Å, which is in agreement with the reported values for a-GaOOH [27]. a-GaOOH is the most thermodynamically stable polymorph that is obtained by dissolution-precipitation of the amorphous Ga(OH) 3 precursor [7,28]. Therefore, the dipeptide is supposed to play key role in transforming Ga(OH) 3 to a-GaOOH through its catalytic activity.…”

Synthesis of Gallium Oxide Hydroxide Crystals in Aqueous Solutions with or without Urea and Their Calcination Behavior

“…Pokrovski et al 29 determined the thermodynamic properties of ␣-GaO(OH), at temperatures up to 700 K, by using low-temperature heat capacity and solubility tests, and their data confirmed that gallium oxide hydroxide was the stable phase in the Ga-O-H system up to 300°C. It should be noted that ␣-GaO(OH) is also a structural analogue of a group of previously studied oxidic hydrates, such as ␣-ScO(OH), 30 groutite (␣-MnO(OH)), 31 and goethite (␣-FeO(OH)).…”

Synthesis of Gallium Oxide Hydroxide Crystals Aqueous Solutions with or without Urea and their Calcination Behayior

“…Precipitation of GaO(OH) in solutions containing dissolved gallium chloride, on the addition of various alkalis (such as NaOH, KOH, NH 4 OH, NaHCO 3 , and Na 2 CO 3 ), has been studied by Sato et al 26 These authors reported that the freshly precipitated (at pH values varying between 6 and 10) precursors were all X-ray amorphous 26 and converted to crystalline ␣-GaO(OH), with an orthorhombic crystal structure similar to that of diaspore (␣-AlO(OH)), 27,28 only after about 1 day of aging in their basic mother liquors. Pokrovski et al 29 determined the thermodynamic properties of ␣-GaO(OH), at temperatures up to 700 K, by using low-temperature heat capacity and solubility tests, and their data confirmed that gallium oxide hydroxide was the stable phase in the Ga-O-H system up to 300°C. It should be noted that ␣-GaO(OH) is also a structural analogue of a group of previously studied oxidic hydrates, such as ␣-ScO(OH), 30 groutite (␣-MnO(OH)), 31 and goethite (␣-FeO(OH)).…”