In-situ observation of the crystal growth process by X-ray scattering at small glancing angle incidence

我们建造了一台紧凑的超高真空(UHV)X射线衍射仪，用于表面掠过X射线散射。利用该仪器对PbSe(III)表面的外延生长进行了原位观察，并在旋转阳极源的情况下，成功地观察到了镜面反射X射线强度的振荡，显示了表面的逐层生长。但对于晶体生长的监测来说，振荡的幅度很小。在此基础上，构建了新的散射X射线强度二维角分布测量系统。利用该系统对晶体生长过程中表面散射X射线强度的二维角分布进行了原位观测，并用掠角X射线散射法对PbSe(III)晶体的生长表面进行了估算。首先，我们通过探测镜面反射X射线，成功地实现了对PbSe(III)的逐层生长的原位观察。接下来，我们观察了晶体生长过程中来自表面的散射X射线强度的二维角分布，并从另一个角度估计了镜面反射X射线和散射X射线的强度比。用该装置对一些工业材料表面进行了机械抛光实验：(1)纯铁多晶表面(铁素体，纯度3，9)在500℃焙烧前后的机械抛光。(2)高速钢(SKH钢)在其制造工艺的不同阶段离子镀TiN的表面。

We have constructed a compact ultrahigh-vacuum (UHV) x-ray diffractometer for surface glancing x-ray scattering. By this instrument, in situ observation of the epitaxial growth of PbSe(III) surfaces performed, and the oscillation of the specularly reflected x-ray intensity showing the layer-by-layer growth of the surface was successfully observed even using a rotating-anode source. But the amplitudes of the oscillation were very small to utilize the monitor of crystal growth. Then we constructed new measurement system of two dimensional angular distribution of scattered x-ray intensity. By this system we tried to perform in situ observation of the two dimensional angular distribution of scattered x-ray intensity from the surfaces during crystal growth.The experiment was estimation of the growing surface of PbSe(III) by means of glancing angle x-ray scattering method. At the first we success to perform in situ observation of layer-by-layer growth of PbSe(III) by the detection of the specularly reflected x-ray from the surface. Next we observed the two dimensional angular distribution of scattered x-ray intensity from the surfaces during crystal growth, and we estimated the intensity ratios of the specularly reflected x-rays and the scattered x-rays at another angle. We could not find obvious oscillation in the ratios.The other experimants were performed on some industrial materials surfaces by this apparatus ; (1) mechanically polished pure iron polycrystal surfaces (ferrite, 3 nines purity) before and after the baking at 500。C for 20 hr in a vacuum of 1 0^<-8> Torr, which shows a sudden broadening of the scattered profiles due to surface roughening, and (2) High Speed Steel (SKH steel) surfaces which are ion-plated by TiN at different stages in their manufacturing processes.