Identifying and quantifying the mechanism of electron beam induced damage and recovery in hydroxyapatite

Abstract

Studies of electron beam induced damage in synthetic HA powder produced by standard solution-precipitation are reported. Under intense irradiation, such as that produced by a focused field emission source used when analysing a grain boundary or heterophase interface, it was found that the material damages transforming to cubic calcium oxide. The damage process was quantitatively monitored as a function of total fluence, fluence rate, accelerating voltage and specimen temperature by measuring the Ca/P ratio determined by EDX or EELS. Conclusions as to the exact damage and also recovery mechanisms in operation are drawn and the conditions required for limited-damage measurement are derived. © 2008 IOP Publishing Ltd.