A historical introduction to the symmetries of magnetic structures: Part 1. Early quantum theory, neutron powder diffraction and the colored space groups

TL;DR

This paper reviews the historical development of symmetry concepts in magnetic structures, focusing on early quantum theory and neutron diffraction, culminating in the derivation of colored space groups.

Contribution

It provides a historical overview of the evolution of symmetry frameworks for magnetic structures, emphasizing the derivation of colored space groups from early quantum models.

Findings

Derivation of black and white space groups

Introduction of colored space groups

Historical connection between symmetry schemes

Abstract

This paper introduces the historical development of the symmetries for describing magnetic structures culminating in the derivation of the black and white and colored space groups. Beginning from the Langevin model of the Curie law, it aims to show the challenges that magnetic ordering presented and how different symmetry frameworks were developed to meet them. As well as explaining core ideas, later papers will show how the different schemes are connected. With these goals in mind, the maths related is kept to the minimum required for clarity.