Chemical and Hydrostatic Pressure Effect on Charge Density Waves of SmNiC2

Abstract

Using a first-principles density functional theory method, we have investigated the chemical and the hydrostatic pressure effects on the charge density wave (CDW) properties of the quasi-one-dimensional (1D) compound SmNiC2. With increasing pressure, the relative 1D anisotropy of the electronic structure along a direction is enhanced because of its Ni chain structures. From the analysis of the Fermi surface and the generalized susceptibility, we also find that the Fermi surface nesting is enhanced along the modulation vector q(1) = (0.5, 0.52, 0) but is suppressed along q(R) = (0.5, 0.5, 0.5) under pressure. The enhancement of 1D anisotropy of SmNiC2 under pressure is responsible for increasing CDW strength along q(1). We suggest that this quantitative analysis could be used for analysis of the pressure effect on CDW materials.