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通过热释光方法研究了PbWO4(PWO) ,PWO :Y3+ ,PWO :Gd3+ 多晶粉末及PWO ,PWO :Y单晶的低温 (<30 0K)热释光现象 .多晶粉末中 ,掺杂Y3+ 或Gd3 + 都会大大降低甚至消除 2 0 0K附近的热释光峰 ,同时产生新的热释光峰 ,分别位于 12 5和 15 0K(掺Y掺Gd) .这表明掺三价离子除了起到电荷补偿作用以减少Pb3+ ,O- 浓度外 ,还可以产生新的陷阱能级 .对于PWO :Y单晶 ,掺杂Y3 + 可以消除 2 5 3K的热释光峰 ,即消除较深 (～ 0 .89eV)的陷阱 ,但PWO单晶中较浅的陷阱 (～ 0 .42eV)对应 130K热释光峰仍然存在 ,对此进行讨论 ,它最可能源于氧空位缺陷 .根据Pb3+ ,Gd3+ ,Y3 + 的电子库仑势不同 ,在PWO晶体中替代Pb2 + 后形成的电子陷阱深度有别 (EPb>EGd >EY) ,从而解释了相应的热释光峰值温度的不同
The thermoluminescence of PbWO4 (PWO), PWO: Y3 +, PWO: Gd3 + polycrystalline powders and PWO, PWO: Y single crystal at low temperatures (<30 0K) Or Gd3 + will greatly reduce or even eliminate the near 200 KH TL peak, and produce new TL peaks, respectively, at 125 and 15 0K (doped with Y-doped Gd). This shows that doping with trivalent ions in addition to play Charge compensation can reduce the concentrations of Pb3 + and O-, but also generate new trap levels.For PWO: Y monocrystal, doping Y3 + can eliminate the thermoluminescence peak of 2 53K, .89eV), but the shallow trap (~ 0.42eV) in the PWO single crystal corresponds to the 130K TL peak, which is most likely to originate from oxygen vacancy defects.According to Pb3 +, Gd3 +, Y3 + Electrons have different coulomb potentials. The depth of electron traps formed after the substitution of Pb2 + in the PWO crystal is different (EPb> EGd> EY), thus explaining the difference in the corresponding thermoluminescence peak temperature