Lattice distortion tuning resistivity Invar effect in high-entropy alloys

Abstract

<p>Materials with an ultra-low temperature coefficient of resistivity are desired for the temperature and flow sensors in high-precision electronic measuring systems. In this work, the Kubo-Greenwood formula, implemented in <em>ab initio</em> molecular dynamics simulations, is employed to predict the finite-temperature resistivity of multicomponent alloys with severe lattice distortion. We observe a tiny change in resistivity over a wide temperature range in high-entropy alloys. The electronic resistivity Invar effect in B2 Ni25⁢Co25⁢(HfTiZr)50 Elinvar alloys results from a balance between intrinsic and residual resistivity. This effect is associated with atomic displacements from ideal lattice sites, which are caused by lattice thermal vibrations and chemical disorder-induced lattice distortions. It is further evidenced by a decrease in lattice distortion with temperature and changes in the electronic density of states.<br></p>