Recently published
Tailoring magnetocaloric effect in all-d-metal Ni-Co-Mn-Ti Heusler alloys: a combined experimental and theoretical study
2020/11/18
A. Taubel, B. Beckmann, L. Pfeuffer, N. Fortunato, F. Scheibel, S. Ener, T. Gottschall, K. P.Skokov, H. Zhang, O. Gutfleisch,
Acta Mater. 201, 425-434 (2021).
Novel Ni-Co-Mn-Ti all-d-metal Heusler alloys are exciting due to large multicaloric effects combined with enhanced mechanical properties. We show that an optimized heat treatment leads to very sharp phase transitions in bulk alloys with large isothermal entropy changes. Differences of as-cast and annealed samples are attributed to different grain structures and stoichiometric (in)homogenieties leading to differently sharp martensitic transitions We develop alloy design rules for tuning the magnetostructural phase transition and evaluate specifically the sensitivity of the transition temperature towards the externally applied magnetic and set up a universal phase diagram. Our collaboration with the TMM group, using Density Functional Theory, reveal a correlation of TC with the stoichiometry as well as with the order state of the austenite. Thus, this new series of Heusler alloys can be differentiated from classical Ni-Mn-In or Ni-Mn-Sn compounds. Our combined approach of experiment and theory allows for an efficient development of new alloy systems for multicaloric applications (supported by ERC AdvGr Cool Innov and CRC270).
