Mo含量对Ti-Mo合金氢同位素效应的影响  

Effect of Mo Content on the Hydrogen Isotope Effect of Ti-Mo Alloy Hydrides

作　　者：王伟伟[1] 龙兴贵[1] 刘文科[1] 黄刚[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《同位素》2009年第3期156-159,共4页Journal of Isotopes

摘　　要：采用磁悬浮熔炼法制备了固溶体合金TiMox（x=0．03、0．13、0．25、0．50、1．00，x为Mo与Ti原子数之比），经活化后与H—D混合气（D原子占50％）反应，反应平衡后用质谱分析气相中H和D的含量。根据反应前气相中H和D的含量，由质量守恒定律求得固相中H和D的含量。根据气、固两相中的氕氘原子数之比（D／H），由公式α（H-D]=（ED3／[H]）（目目）／（ED3／[H]）（气相）计算得到H-D分离因子α（H-D）。结果表明：20℃下，x0．03～1．00时，α（H-D）〉1．00，合金氢化物表现为正同位素效应。随着Mo含量的增加，α（H—D）由1．04增加到1．27；x〉0．50时，α（H-D）基本保持不变。2／7—0．03时α（H-D）≈1．00，合金表现为零同位素效应。根据以前热分析实验结果，TiMo0.03吸氢后析出大量负同位素效应的TiH2，并有少量正同位素效应的Ti—Mo合金氢化物，零同位素效应是两者共同作用的结果。根据Mo含量和分离因子的关系，室温下H原子倾向于占据4Ti四面体间隙位置，而D原子倾向于占据能量较高的3TilMo四面体间隙位置。The alloys with various Mo content TiMox（x=0.03, 0.13, 0.25, 0.50, 1.00, atomic ratio） were prepared with electromagnetic levitation technique. The alloys after activation reacted rapidly with H-D gas mixture （D% =50%）, the composition of the mixture in equilibrium of isotope exchange was determined using a mass-spectroscopy. H-D separation factor α（H-D） was defined as （[D]/[H]）s/（[D]/[H]）, in which [D]/[H]s refers to the atomic ratio of D and H in solid phase, and [D]/[H]g refers to the atomic ratio of D and H in gas phase. The results showed that at 20℃, x=0. 03-1. 00, α（H-D）〉1. 00, D prefered to stay at solid phase, and the preference becomed stronger as the Mo content increases, with α（H-D） rising from 1. 04 to 1. 27. ℃,-D〉 kept nearly unvaried when x=0. 50-1. 00. α（H-D）≈1. 00 when x= 0. 03, namely TiMo0.03 hydride showed zero effect, through previous TG-DSC analysis results, the hydride contains TiH2 with negative effect, and Ti-Mo hydrides with positive effect, so it is the total effect of the two hydrides with oppositive effect. From the relationship between the Mo content and α（H-D）, H atom prefers to take 4Ti tetrahedral in terstice, whereas D atom tends to take 3TilMo position in which the energy level is higher than that of 4Ti position.

关 键 词：氢同位素效应 Ti—Mo固溶体合金 H—D分离因子 质谱分析 

分 类 号：TL93[核科学技术—辐射防护及环境保护] O613.2[理学—无机化学]