Synthesis of novel Ti-alloy hydrides with high hydrogen content

用原位同步辐射X射线衍射法研究了一种CsCl型TiFe合金在5 GPa873K下的氢化过程。氢在TiFe中形成固溶体后，TiFe的金属晶格发生有序-无序相变，生成体心立方的TiFe氢化物。氢化反应后体心立方氢化物的晶胞体积增加了21.0%。为了估算体心立方氢化物的氢含量，比较了体心立方氢化物的晶格体积和高温高压条件下体心立方氢化物的晶格体积。结果表明，体心立方相的晶格体积与体心立方氢化物的晶格体积几乎相等，因此体心立方氢化物的氢含量与体心立方氢化物的氢含量几乎相等。

We investigated the hydrogenation of a CsCl-type TiFe alloy at 5 GPa and 873 K by in situ synchrotron radiation X-ray diffraction measurements. After formation of a solid solution of hydrogen in TiFe, an order-disorder phase transition in the metal lattice of TiFe occurred, which yielded a BCC TiFe hydride. The unit cell volume of the BCC hydride increased by 21.0% after the hydrogenation reaction. The volume expansion was larger than that of a gamma hydride TiFeH_x (x = 1.9) prepared by hydrogenation near ambient conditions.In order to estimate the hydrogen content of BCC hydride, we compared its lattice volume with the lattice volume of the gamma hydride at same high pressure and high temperature conditions. As a result, the lattice volume of BCC phase was almost equal to that of the gammma hydride, therefore, the hydrogen content of BCC hydride was almost equal to the gamma hydride.