The lattice relaxation and neutron inelastic scattering of (Cu Ni)sub(3-x) Alsub(1+x) alloy which causes thermo-elastic martensite transformation

The time of flight experiment was carried out for the study of the energy reduction of phonon following lattice relaxation. The composition of a measured sample was Cu 68 at.%, Ni 4 at.%, and Al 28 at.%. The T mode and the L mode on <100> axis were measured. Softening was seen at a position between q=(7/10, 0, 0) and q=(8/10, 0, 0) in the Tsub( al) mode on the <100> axis. This corresponds to the behavior of the Tsub( al) mode on <100> axis in the phonon dispersion relation of β-AuCuZn alloy. The present experiment was preliminary experiment, and the purpose of the experiment was to estimate the scattering intensity of phonon peaks. It was expected that the phonon peak on <100> axis was able to be observed with a counter of 2theta=580. The up-scattering peaks due to T mode and L mode phonons were seen in the spectrum of 8 hour neutron irradiation. The resolving power was about 0.5 MeV. It was found that half-day measurement was enough to observe phonon peaks. The measurement of the phonon dispersion relation at 00K was also made, and the result was in good agreement with the result at low energy. (Kato, T.)