US EPA

8444133 

Journal Article 

Chemically tuning between ferromagnetism and antiferromagnetism by combining theory and synthesis in iron/manganese rhodium borides 

Martin, JD 

2003 

16 

8 

496-504 

English 

In the series of three articles (title reference and references 1 and 2), the authors clearly lay out a semiquantitative theory for understanding the occurrence of ferromagnetism and antiferromagnetism in metallic systems. They demonstrate that the chemical principles giving rise to Jahn-Teller and Peierls structural distortions also provide the basis for understanding electronic structural distortions giving rise to magnetic ordering phenomena. The authors then put their semiquantitive theory to the test by synthesizing a variety of intermetallic phases to demonstrate the fine-tuning between ferromagnetism and antiferromagnetism based on the valence electron count of the material. It would be interesting for them to expand their electronic structure considerations to understand the meta-magnetism reported for systems with intermediate electron counts,s where clearly a competition between the ferromagnetic and antiferromagnetic types of electronic distortions is observed. Finally we note that as with most semiquantitative theories, there is some dispute in the literature regarding the validity of the authors' approach to understanding magnetism in metals.9 Nevertheless, in these works, the authors clearly reduce complex properties of magnetism to chemical principles that can readily be applied for the design and synthesis of new materials.