金属铈在过量氘气氛下的腐蚀行为研究

Corrosion behavior of metallic cerium in excess deuterium

摘要:

本工作采用压力-体积-温度系统(PVT)与热台显微镜(Hot-stage microscope, HSM)相结合的方法，研究了铈(Ce)在过量氘(D2)气氛下的腐蚀行为；采用X射线衍射(XRD)和热脱附谱(TDS)方法分别考察了铈-氘反应产物的相组成及热稳定性。结果表明，铈在室温、初始压力43 kPa的氘气氛下，可快速与氘发生反应，形成饱和的铈氘化物CeD3，样品发生严重粉化；对饱和铈氘化物在不同温度下加热，可得到一系列不同氘含量的铈氘化物；所制备的铈氘化物在室温下均具有与金属铈类似的面心立方(fcc)结构，铈形成CeD2的体胀约为24.3%，但随着氘含量的增加，铈氘化物会发生反常的体积收缩现象；热脱附谱测试表明CeD3在120 ℃附近即可发生分解，而CeD2则可稳定至600 ℃以上。

Abstract:

The corrosion behavior of cerium (Ce) in excess deuterium (D2) was investigated by the pressure-volume-temperature system (PVT) and the hot-stage microscopy (hot-stage microscope, HSM). The phase composition and thermal stability of cerium-deuterium reaction products were investigated by X ray diffraction (XRD) and thermal desorption spectroscopy (TDS). The results show that cerium can quickly react with deuterium to form saturated cerium deuteride (CeD3) at room temperature and the initial deuterium pressure of 43 kPa. After the reaction, the sample is seriously pulverized. A series of cerium deuterides, which have different content of deuterium, can be obtained by heating the saturated cerium deuteride at different temperature. The cerium deuterides have the face-centered cubic (fcc) structure similar to cerium at room temperature. The volume expansion ratio of CeD2 is about 24.3% relative to Ce. However, with the increase of deuterium content, anomalous volume shrinkage of cerium deuteride emerges. Thermal desorption spectrums show that CeD3 could decompose at 120 ℃, but CeD2 could be stable above 600 ℃.