Huang diffuse x ray scattering from lattice strains in high-concentration Ta-H alloys

The diffuse scattered x ray intensity close to several reciprocal lattice points (hh0) was measured at room temperature in single-crystal Ta-H alloys. The displacement field of dissolved hydrogen in Ta can be treated as a linear superposition of single-defect fields even at concentrations as high as c(H/Ta) = 0.111. In order to determine the strength and the symmetry of the double force tensor, Psub(ij) describing the displacement field, a static Debye-Waller factor was calculated, lowering both the Bragg and the diffuse intensity. After evaluating the static Debye-Waller factor, which is a function of the defect concentration, the displacement field and the scattering vector, Psub(ij) = Δsub(ij) (3.36 +- 0.16)eV was determined. The cubic symmetry and the strength of Psub(ij) are in good agreement with results which have been obtained at lower hydrogen concentrations. (author)