Pseudoelasticity of SrNi₂P₂ Micropillar via Double Lattice Collapse and Expansion

Abstract

The maximum recoverable strain of most crystalline solids is less than 1% because plastic deformation or fracture usually occurs at a small strain. In this work, we show that a SrNi 2 P 2 micropillar exhibits pseudoelasticity with a large maximum recoverable strain of ∼14% under uniaxial compression via unique reversible structural transformation, double lattice collapse−expansion that is repeatable under cyclic loading. Its high yield strength (∼3.8 ± 0.5 GPa) and large maximum recoverable strain bring out the ultrahigh modulus of resilience (∼146 ± 19 MJ/m 3 ), a few orders of magnitude higher than that of most engineering materials. The double lattice collapse−expansion mechanism shows stress−strain behaviors similar to that of conventional shape-memory alloys, such as hysteresis and thermomechanical actuation, even though the structural changes involved are completely different. Our work suggests that the discovery of a new class of high-performance ThCr 2 Si 2 -structured materials will open new research opportunities in the field of pseudoelasticity.

Strain-induced magnetic anisotropy of multi-domain epitaxial EuPd2 thin films

“…The energy cutoff was set to 500 eV. Each calculation for the magnetic anisotropy energy (MAE) consists of a three-step procedure [20]: In the first step, starting from an already relaxed structure at ε = 0% strain, the structure was further relaxed for different strain values ε = ±0.5%. The strain was introduced by using the fcc primitive unit cell with a strain tensor…”