Valence band-satellite, temperature dependent magnetic and spectral study of {\alpha}-Fe

TL;DR

This study explores how correlations and plasmonic excitations affect the valence band satellite, magnetic, and spectral properties of lpha-Fe across temperatures, revealing orbital-selective coherence loss and magnetization collapse near the Curie temperature.

Contribution

It combines advanced theoretical methods to identify the valence band satellite and its temperature-dependent behavior in lpha-Fe, highlighting orbital-selective phenomena.

Findings

Valence band satellite at  eV supported by DFT+DMFT and G0W0 calculations.

Temperature-dependent loss of coherence in e_g states near T_c.

Orbital-selective collapse of magnetization at the Curie temperature.

Abstract

We investigate the influence of correlations and plasmonic excitation on valence band-satellite of $\alpha$-Fe, along with magnetic and spectral properties as function of temperature. Coulomb interaction parameters are obtained by systematically employing various schemes in constrained random phase approximation (cRPA). This study identifies the presence of valence band satellite in Fe at $\sim$6 eV binding energy supported by (i) substantial incoherent spectral weight in the valence band spectra obtained from Density Functional Theory plus Dynamical Mean Field Theory (DFT+DMFT) and (ii) plasmonic excitations in the frequency range $\sim$6-8 eV suggested by $G_0W_0$ calculations. We note presence of significant contribution of temperature-dependent Pauli-spin susceptibility indicating competing degree of itinerancy. $e_g$ state shows a strong temperature driven non-Fermi-liquid behavior emerging near $T_c$. Our results reveal a high-temperature orbital-selective loss of coherence eventually leads to a orbital selective collapse of magnetization at $T_c$, suggesting a ferromagnetic phase characterized by strong correlation- and temperature- dependent spectral features.