Effects of iron spin transition on the electronic structure, thermal expansivity and lattice thermal conductivity of ferropericlase: a first principles study

作者：Yalan Song, Kaihua He, Jian Sun, Chaojie Ma, Miao Wan, Qingbo Wang, Qili Chen · 发表于：Scientific Reports · 年份：2019 · DOI：10.1038/s41598-019-40454-4 · 被引用次数：11 · 研究领域：High-pressure geophysics and materials、Advanced Condensed Matter Physics、Magnetic and transport properties of perovskites and related materials

The effects of the spin transition on the electronic structure, thermal expansivity and lattice thermal conductivity of ferropericlase are studied by first principles calculations at high pressures. The electronic structures indicate that ferropericlase is an insulator for high-spin and low-spin states. Combined with the quasiharmonic approximation, our calculations show that the thermal expansivity is larger in the high-spin state than in the low-spin state at ambient pressure, while the magnitude exhibits a crossover between high-spin and low-spin with increasing pressure. The calculated lattice thermal conductivity exhibits a drastic reduction upon the inclusion of ferrous iron, which is consistent with previous experimental studies. However, a subsequent enhancement in the thermal conductivity is obtained, which is associated with the spin transition. Mechanisms are discussed for the variation in thermal conductivity by the inclusion of ferrous iron and the spin transition.