Li_2B_4O_7の熱ルミネセンスの発光機構

概要

論文の詳細を見る
Thermoluminescence (TL) characteristics of Li_2B_4O_7 doped with Cu or some rare earth elements as activator were studied and the emission mechanism of TL was proposed. TL grow curves of Cu- doped crystallized glasses were changed with crystallizing temperature and TL emission was not observed from amorphous Li_2B_4O_7. The change in crystallizing temperature resulted in the change of Cu^<1+> content in the crystal, which markedly affected the TL characteristics of Li_2B_4O_7. TL intensities did not simply increase with increasing amount of Cu doped, but showed maximum values at about 0.05 mol% Cu. Emission spectra of Li_2B_4O_7 doped with Cu or some rare earth elements similarly showed maxima at about 370 nm. The results in ESR measurements indicated that a part of Cu^<1+> in Cu-doped Li_2B_4O_7-crystallized glass was converted to Cu^<2+> by irradiation of X- ray. The shape of 70℃- and 150℃- glow peaks of Cu-doped Li_2B_4O_7 were explained by the "first order kinetics" model, and the activation energies were estimated to be 0.8 and 1.1 eV, respectively. The emission mechanism of TL was proposed as follows : electron holes created by irradiation were trapped by Cu^<1+> centers, and after liberated from the trap centers by thermal energy, the holes combined with electrons at electron trap centers, giving rise to the emission of TL.
社団法人日本セラミックス協会の論文
1989-05-01