抄録
β-Tricalcium phosphate (β-Ca3(PO4)2, β-TCP) is an attractive function material as a thermoluminescence (TL) phosphor1). We investigate TL properties and electron spin resonance (ESR) characterization on dysprosium-doped β-tricalcium phosphate phosphor (β-Ca3(PO4)2:Dy, β-TCP:Dy). β-TCP:Dy (Dy/Ca atomic ratio:0~32.4×10-3) was synthesized by a heat treatment of dysprosium-doped amorphous calcium phosphate (Ca3(PO4)2•nH2O:Dy, ACP:Dy) at 1100 degrees in air for 2 h. Detailed analysis of the TL peak shape can give information on the trap depth (activation energy ε), indicating the trap depth of ε = 1.1 eV from Hoogenstraaten′s method2). The ESR spectra of β-TCP:Dy after X-ray irradiation revealed the existence of a hydrogen atom in β-TCP:Dy and the good correlation between the unpaired electron density of hydrogen atom and TL intensity was concluded. 1) H.Ohtaki, Y.Fukuda, N.Takeuchi, Radiation Protection Dosimetry, 47, 119-122 (1993). 2) W.Hoogenstraaten, Philips Research Reports, 13, 515-693 (1958).
