Order-Disorder Transitions in the Vanadium-Hydrogen System Measured by Perfect-Crystal Neutron Small-Angle Scattering

Abstract

The solubility limits for hydrogen in vanadium were determined using small-angle neutron scattering. In addition, the neutron transmission in dependence of the hydrogen concentration at 170 °C (pure α-phase) and at 20 °C (α + β-phase) was measured. The total cross section of the proton in the α-phase was found to be nearer to the free than to the bound value. The Guinier-approximation is used to examine the small-angle scattering of precipitates in the β-phase V2H. The features of perfect-crystal neutron small-angle scattering for the precise transmission measurement and for the investigation of the very small Q-range are demonstrated.