title: Understanding the phase transitions of the Ni2MnGa magnetic shape memory system from first principles.
abstract: The free energies of the austenite, the (modulated) premartensite and the unmodulated martensite of Ni2MnGa are determined using density functional theory and including quasiharmonic phonons and fixed-spin-moment magnons. This approach very well reproduces the complete phase sequence (martensite<-->premartensite<-->austenite) of stoichiometric Ni2MnGa as a function of temperature. By analyzing the relevant free energy contributions, we also understand the delicate interplay of phonons and magnons driving both phase transitions.
authors.affiliation: Max-Planck-Institut für Eisenforschung GmbH, D-40237, Düsseldorf, Germany. uijttewaal@mpie.de
authors.forename: M A
authors.initials: MA
authors.lastname: Uijttewaal
authors.forename: T
authors.initials: T
authors.lastname: Hickel
authors.forename: J
authors.initials: J
authors.lastname: Neugebauer
authors.forename: M E
authors.initials: ME
authors.lastname: Gruner
authors.forename: P
authors.initials: P
authors.lastname: Entel