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在以前工作的基础上,利用在频率平面上进行空间滤波的方法,研究了α-LiIO3单晶在静电场作用下,空间电荷分布引起的衍射光强变化的弛豫行为。得出了弛豫过程的唯象表达式,发现其中的弛豫参数依赖于温度和电压的大小以及所加电压为同号或异号电压,且随样品的不同而变化。在低温下,衍射会被“冻结”:即在“冻结”温度(~-25℃)以下加电压,衍射增强不显著;在“冻结”温度以上加电压,然后降至“冻结”温度以下,衍射光强度仍保持高温时增强后的数值;撤去电压,因加电压所增加的衍射并不消失。On the basis of our earlier work, the relaxation behaviors of the light diffraction intensity induced by the distribution of space charge in a-LiIO3 single crystals under the action of an electrostatic field have been investigated by using a space filter. The empirical expressions of the relaxation process were obtained. It was found that the parameters involved change with the temperature and from specimen to specimen, as well as depend both on the magnitude and the relative direction of the polarity of the crystal and the electrostatic field applied. When the temperature is lowered below a certain value (≈-25℃), the enhancement diffraction intensity due to the applied field becomes not quite evident. When the electrostatic field is applied at a temperature higher than the "freezing" point and then the specimen is cooled to a temperature below the latter, the magnitude of diffraction intensity enhanced by the applied voltage at higher temperatures remains unchanged, it is so even after removing the voltage. This "freezing" effect is parallel to that observed in the enhancement of neutron diffraction intensity.
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