Abstract
Inelastic neutron scattering and neutron diffraction were used to study a single crystal of the MnGa shape memory Heusler alloy in a wide temperature range covering the parent phase ( K), a premartensitic phase (), and a martensitic ( K) phase region. Several anomalies in the phonon dispersion curves in the parent phase were observed. The premartensitic phase involves a transverse modulation of the parent cubic structure with a simple periodicity of (). The approximately tetragonal lattice of the low-temperature martensite is distorted by transverse modulations with incommensurate wave vectors (), . The observed phenomena are attributed to electron-phonon interactions and anharmonic effects.
- Received 29 March 1996
DOI:https://doi.org/10.1103/PhysRevB.54.15045
©1996 American Physical Society