Temperature-dependent optical and magneto-optical spectra of ferromagnetic BCC Fe
arxiv(2024)
摘要
Optical and magneto-optical properties of magnetic materials have been widely
exploited to characterize magnetic structures and phenomena, however, their
temperature dependence is not well understood. This study implements the
supercell approach with thermal lattice and magnetic disorders to obtain
optical and magneto-optical spectra at finite temperatures based on
Williams-Lax theory. Our results show that large optical spectrum signals are
generated at photon energies below 1 eV, originating from the phonon- and
magnon-assisted intraband transitions as lattice and magnetic temperatures
increase. In addition, the prominent peak near 2.7 eV is redshifted
proportionally to magnetic temperature but depends much less on lattice
temperature. By analyzing unfolded bands, we show that the reduction of
exchange splitting due to the thermal demagnetization causes this redshift. Our
unfolded electronic band structure with magnetic disorder shows band kinks,
which are characteristic evidence of the coupling between electrons and
magnetic excitations. First-order magneto-optical spectra at finite temperature
are also predicted, but due to their small magnitude suffer more from sampling
errors. We discuss the effect of zero-point vibrations and the connection of
these simulations to the Drude model for intraband transitions.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要