Moya Raposo, XavierMañosa, LluísPlanes Vila, AntoniKrenke, ThorstenAcet, MehmetGarlea, V. O.Lograsso, T. A.Schlagel, D. L.Zarestky, Jerel L.2009-12-282009-12-2820060163-1829https://hdl.handle.net/2445/10559Inelastic and elastic neutron scattering have been used to study a single crystal of the Ni$_{54}$Mn$_{23}$Al$_{23}$ Heusler alloy over a broad temperature range. The paper reports the first experimental determination of the low-lying phonon dispersion curves for this alloy system. We find that the frequencies of the TA$_2$ modes are relatively low. This branch exhibits an anomaly (dip) at a wave number $\xi_{0} ={1/3}\approx 0.33$, which softens with decreasing temperature. Associated with this anomalous dip at $\xi_{0}$, an elastic central peak scattering is also present. We have also observed satellites due to the magnetic ordering.6 p.application/pdfeng(c) The American Physical Society, 2006Transformacions martensítiquesTeoria dels reticlesFononsMartensitic transformationsLattice theoryPhononsinfo:eu-repo/semantics/article540296info:eu-repo/semantics/openAccess