Structural Transformations in Iron Borate under High-Temperature Annealing

Scanning electron microscopy and X-ray diffractometry are used to study surface morphology and crystal structure of iron borate FeBO3 annealed at different temperatures. Temperature limits of the structural stability are determined. It is shown that recrystallization to iron orthoborate Fe3BO6 and hematite α-Fe2O3 takes places at temperatures of 800–900°C and above 900°C, respectively.