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在1060—1550℃温度范围内,以~(18)O作示踪元素,用气体—固体同位素转换技术测定YAG单晶中氧的自扩散系数。在原生态的晶体中,氧离子的体扩散系数可由D=5.24×10~(-7)exp(-325000J/mol/RT)m~2/s表示。这个系数取决于扩散退火前的热处理气氛。晶体氧空位电平的效应归因于色心缺陷的形成和所含杂质离子的化合价变化。认为这种活化能是由于氧离子迁移所致。YAG单晶小面区的氧空位浓度比无小面区的要高。
In the temperature range of 1060-1550 ℃, the self-diffusion coefficient of oxygen in YAG single crystal was determined by gas-solid isotope conversion technique using ~ (18) O as tracer element. The bulk diffusion coefficient of oxygen ions can be expressed by D = 5.24 × 10 -7 (-325 000 J / mol / RT) m ~ 2 / s in the original crystal. This factor depends on the heat treatment atmosphere before diffusion annealing. The effect of crystal oxygen vacancy levels is attributed to the formation of chromophore defects and valence variations of impurity ions contained therein. It is believed that this activation energy is due to oxygen ion migration. Oxygen vacancy concentration in YAG single crystal facet is higher than that in non-facet.