J. Phys. IV France 03 (1993) C8-287-C8-290
Phase separation in titanium hydrides studied by small-angle neutron scatteringI.O. BASHKIN1, A.I. KOLESNIKOV1, V.Yu. MALYSHEV1, E.G. PONYATOVSKY1, S. BORBÉLY2, L. ROSTA2 and G. PÉPY3
1 Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka 142432, Russia
2 Research Institute for Solid State Physics, P.O. Box 49, 1525 Budapest, Hungary
3 Laboratoire Léon Brillouin, CEN Saclay, 91191 Gif-sur-Yvette cedex, France
Various phases of titanium hydrides with differing hydrogen and deuterium content are studied by small-angle neutron scattering. The low temperature metastable [MATH] phase produced by quenching under high pressure shows small, but pronounced scattering at liquid nitrogen temperature. At 140 K a very abrupt increase in the scattered intensity is detected, more than one order of magnitude for less than 30 s. The scattering from the room temperature (α+γ) phase is analysed by the fractal as well as the random two-phase model. The fit does not prove fractal behaviour of the α-Ti precipitates in the γ-TiH(D)1 matrix. A good representation is obtained in a random two-phase model, giving about 50 and 60 Å correlation lengths, independently of the deuterium or hydrogen content. For the α phase, only the asymptotic behaviour of the scattering curves is observed in the scattering vector range covered in the experiments.
© EDP Sciences 1993