DEPENDENCE OF THERMOLUMINESCENCE AND EXOELECTRON EMISSION ON CERAMIC CHARACTER OF BEO

Cold-pressed pellets of unfired BeO, called Thermalox 995, have been fired at temperatures between 400 degree and 1900 degree C. The thermally stimulated exoelectron emission (TSEE), thermoluminescence (TL), and electron paramagnetism (EPR) have been measured and correlated with sintering and grain growth. Changes in TL and TSEE sensitivity are as much as five, and two and a half orders in magnitude, respectively. The changes in concentration of the paramagnetic trapping centers correlate fairly well with the changes in TL sensitivity showing that the two are intimately related. The TSEE data show a markedly different trend; the traps are of a different type from those producing TL and are not detected by EPR. The most satisfactory radiation dosimeters are obtained after firing at 1300 degree C when the mean grain size is about 7 mu m.