H+对高压处理后的β-LiIO3转变为α相的作用

室温下经过不同的高压(最高为80kbar)作用后的β-LiIO₃的X射线衍射实验表明:1)受压后的β-LiIO₃在大气中发生的β→α相转变中,高压的作用是促使α相晶核形成。成核率N与压力P的关系接近于N∝e^kp(k=26.8/bar);2)受压力处理后的β-LiIO₃中的α相量在大气中的明显增加,可归结为大气中水分子在α相晶核表面上解离产生的氢离子引起了α晶核的迅速长大,这一论断受到了H⁺注入产生类似效应的支持。 关键词：

EFFECT OF H+ ON THE β→α TRANSITION IN β-LiIO3 AFTER HIGH PRESSURE TREATMENT

Using the X-ray diffraction method, we have investigated the effects of high pressure and H⁺ impregnation on β→α transition in β-LiIO₃ crystals. The samples had been subjected to high pressure treatment (up to 80kb)at room temperature and then preserved in ordinary environmental condition for different periods of time. The experimental results show that in β→α transition in the samples treated as above the pressure can be understood to play a role of promoting the nucleation of a -phase in β-matrix, and the pressure dependence of the rate of nucleation N can be expressed in the form of N ∝e^kp (k= 26.8/bar). The significant increase of quantity of α-phase in such samples may be attributed to the rapid growth of α-LiIO₃ nucleus under the influenle of H⁺ formed through the dissociation of adsorped water molecules on the surface of a nucleus. This conclusion is supported by the similar effects in the experiment of H⁺ impregnation of pressurized β-LiIO₃ samples.