Evolution of soft-phonon modes in Fe–Pd shape memory alloy under large elastic-like strains. (15th February 2016)

• Record Type: Journal Article
• Authors: Seiner, Hanuš; Stoklasová, Pavla; Sedlák, Petr; Ševčík, Martin; Janovská, Michaela; Landa, Michal; Fukuda, Takashi; Yamaguchi, Takashi; Kakeshita, Tomoyuki
• Is Part Of: Acta materialia. Volume 105(2016)
• Page Start: 182
• Page End: 188
• Publication Date: 2016-02-15
• Subjects: Ferromagnetic shape memory alloy -- Anisotropic elasticity -- Single crystal -- Phase transitions -- Surface acoustic waves (SAW); Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2015.12.025
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: We study elastic anisotropy of a disordered Fe–Pd alloy under reversible elastic-like strains up to 4.3% by means of ultrasonic methods. The evolution of the full tetragonal tensor of elastic constants with a [001]-prestress ranging from 0 to 200 MPa is obtained, which enables an analysis of the change of the low-frequency limit of the soft-phonon structure. It is observed that while the anisotropy of the elastic moduli further increases, giving rise to an anomalous anisotropy factor of A > 50, the phonon branches stiffen. This means that, unlike for conventional shape memory alloys, the tetragonal crystal structure induced by the prestress is more stable than the stress-free cubic structure, although there is no other indication of the stress-induced transition. Graphical abstract: