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TT: Fachverband Tiefe Temperaturen
TT 68: Superconductivity: Properties and Electronic Structure
TT 68.14: Talk
Thursday, March 21, 2024, 13:00–13:15, H 3010
Cousin of Fe-based Superconductors SrNi2P2: electronic structure, superelasticity and elastocaloric cooling — •Adrian Valadkhani1, Seok-Woo Lee2, Paul C. Canfield3, and Roser Valentí1 — 1Goethe University, Frankfurt am Main, Germany — 2University of Connecticut, Connecticut, USA — 3Iowa State University, Ames, USA
SrNi2P2 is a ThCr2Si2-structured intermetallic compound that undergoes various volume collapse transitions under strain. Recently a high recoverable compressive strain rate of 14% [1] was measured for this system. Typical values for such strain rates are less than one percent, which are limited by premature plastic deformation or fracture. This recoverable strain rate also takes place for tensile strain with a maximum of about 5%. For SrNi2P2, a double lattice collapse was proposed as the underlying mechanism. This double lattice collapse comes along with a unique elastocaloric double cooling and heating effect, which contrasts strongly to the one of conventional materials with alternating cooling and heating [2]. In this talk we present ab initio density functional theory (DFT) calculations of the electronic structure of this material under various strain conditions and discuss the microscopic origin of the various collapsed phases observed experimentally, superelasticity and the possibility of employing this class of materials as prototypes for elastocaloric cooling at low temperatures.
[1] S. Xiao et al., Nano Lett. 2021, 21, 19, 7913
[2] S. Xiao, A. Valadkhani, S. Rommel, P. C. Canfield, M. Aindow, R. Valentí, S.-W. Lee, just submitted
Keywords: SrNi2P2; DFT; strain; superelasticity; elastocaloric cooling