|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Hume-Rothery Award Symposium: Alloy Phase Chemistry at the Atomic Level - Opportunities and Challenges
||Local Order and Lattice Dynamics in a Shape Memory Strain Glass Alloy
||Paul Stonaha, Michael Manley
|On-Site Speaker (Planned)
The magnetocaloric effect describes the coupling between a materials temperature and its magnetic state. Modern magnetocaloric devices employ materials which undergo a change in magnetic order coinciding with a martensitic (first-order) phase transition. A drawback of the martensitic transformation is the requirement of large magnetic fields (>2T) and the accompanying structural hysteresis. In this talk, we discuss the magnetocaloric effect in the shape memory alloy Ni45Co5Mn36.6In13.4 near its Curie temperature. We present diffuse neutron and X-ray scattering measurements and discuss the corresponding implied local order within the material. We show this material has a large change in the phonon entropy across the transition driven by the low lying TO [H00] phonon, and that the energy of this phonon changes with an applied magnetic field. Finally, we present the results of frozen phonon calculations that show how the phonon couples to magnetism at the atomic level.
||Planned: Supplemental Proceedings volume