Abstract
FePO4 is a quartz analogue that presents also an α−β phase transition from a P622 to a P32 phase. We describe in this paper the works done in view of obtaining single crystals, and discuss results showing that an incommensurate phase takes place in between α and β phases in a range of 17 C. The main α−β transition appears to be closer to the tricritical point than in quartz and berlinite.