First-principles insights into f magnetism, a case study on some magnetic pyrochlores

TL;DR

This study uses first-principles calculations to explore f magnetism in various magnetic pyrochlore oxides, addressing electronic structure complexities and comparing theoretical results with experimental data.

Contribution

It provides a detailed computational analysis of f magnetism in A2Ti2O7 pyrochlores, incorporating Hubbard U and spin-orbit effects, and discusses challenges like multi-minima solutions.

Findings

Gd2Ti2O7 exhibits the least multi-minima problem.

Calculated spin and orbital moments are compared with experimental data.

Relativistic effects and Hubbard U improve electronic structure accuracy.

Abstract

First-principles calculations are performed to investigate f magnetism in A$_2$Ti$_2$O$_7$ (A=Eu, Gd, Tb, Dy, Ho, Er, Yb) magnetic pyrochlore oxides. The Hubbard U parameter and the relativistic spin orbit correction is applied for more accurate description of the electronic structure of the systems. It is argued that the main obstacle for first-principles study of these systems is the multi-minima solutions of their electronic configuration. Among the studied pyrochlores, Gd$_2$Ti$_2$O$_7$ shows the least multi-minima problem. The crystal electric field theory is applied for phenomenological comparison of the calculated spin and orbital moments with the experimental data.