First-principles dynamical CPA to finite-temperature magnetism of transition metals

TL;DR

This paper introduces a first-principles dynamical CPA method combined with LDA+U to accurately model finite-temperature magnetism in transition metals, capturing key magnetic properties and excitation spectra.

Contribution

It develops a novel theoretical framework integrating dynamical CPA with LDA+U for quantitative finite-temperature magnetic calculations.

Findings

Quantitatively explains high-temperature magnetic properties of Fe, Co, Ni.

Describes Curie temperatures semiquantitatively.

Accurately reproduces excitation spectra in the paramagnetic state.

Abstract

We present here the first-principles dynamical CPA (coherent potential approximation) combined with the tight-binding LMTO LDA+U method towards quantitative calculations of the electronic structure and magnetism at finite temperatures in transition metals and compounds. The theory takes into account the single-site dynamical charge and spin fluctuations using the functional integral technique as well as an effective medium. Numerical results for Fe, Co, and Ni show that the theory explains quantitatively the high-temperature properties such as the effective Bohr magneton numbers and the excitation spectra in the paramagnetic state, and describes the Curie temperatures semiquantitatively.