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

Abstract

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, P_ij, describing the displacement field, the authors calculated a static Debye-Waller factor, 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, P_ij= delta _ij(3.36+or-0.16) eV was determined. The cubic symmetry and the strength of P_ij are in good agreement with results which have been obtained at lower hydrogen concentrations.