A new metallic material — based on the substitution of manganese for iron in an iron–arsenide superconductor — has been discovered in which the microscopic magnets of the electron current carriers provided by the potassium atoms all line up in the same direction at low temperatures whereas the neighboring microscopic magnets of the manganese atoms line up in opposite directions to each other. This material, Ba0.6K0.4Mn2As2, thus exhibits a novel magnetic behavior with ferromagnetic and antiferromagnetic behavior coexisting. Interestingly, the ordered moments in the two magnetic substructures are aligned perpendicular to each other. Understanding what causes this unique magnetic structure may help researchers to understand the mechanism of high temperature superconductivity and to design materials for the new field of spintronics, where electron magnets are used in electronic devices for information processing rather than their charge.
Coexistence of Half-Metallic Itinerant Ferromagnetism with Local-Moment Antiferromagnetism in Ba0.60K0.40Mn2As2