Short Range Order in Interstitial Alloys.

1)用弹性中子漫射法测定了Tio_<3.32>单晶中氧排列的短程有序参数。通过实验强度与理论强度的最小二乘拟合，将近程阶项与总漫射强度分离。氧原子的第一、第三和第五相邻原子排列倾向于被空位包围，而不是被氧原子包围。而第二邻位和第四邻位则优先被氧原子占据。2)通过弹性中子漫射测量，确定了VD_<0.81>单晶中氘排列的短程有序参数。空位-氘原子对的优先构型出现在主钒晶格四面体间隙位的第一、第二和第三邻域，而氘-氘原子对出现在第四邻域。这些特征与T_c下面的有序结构中的特征相似。3)利用中子小角散射研究了Nb-N和Ta-N合金中氮原子的局域原子排列。低Q区的扩散强度揭示了氮原子碎块的存在。

1) Short-range order parameters for oxygen arrangement in single crystal of Tio_<3.32> were determined by measurements of elastic neutron diffuse scattering. The short range order term were separated from the total diffuse intensity by least squares fit of the experimental intensity with a theoretical one. The first-, third and fifth-neighbor atomic arrangement of the oxygen atom has a preference to be surrounded by vacancies rather than by oxygen atoms. While, the second- and fourth-neighbor site are occupied preferentially by oxygen atoms.2) Short-range order parameters for deuterium arrangement in single crystal of VD_<0.81> were determined by measurements of elastic neutron diffuse scattering. The preferential configrations of vacancy-deuterium atom pair are found at first-, second-, and thirdneighbors of tetrahedral interstitial sites of the host vanadium lattice whereas the deuterium-deuterium atom pairs occur at the fourth neighbors. These features are similar to those in the ordered structure below T_c.3) Local atomic arrangements of nitrogen atoms in Nb-N and Ta-N alloys have been studied by neutron small angle scattering. The diffuse intensity of low Q region revealed the existence of the nitorogen atom clasters.