Program Highlights

Direct Observation of Ferrimagnetism in a Multiferroic Hexagonal Ferrite

Xiaoshan Xu, Peter Dowben, and Evgeny Tsymbal
Nebraska MRSEC

Multiferroics is a class of materials that exhibits a coexistence of electric and magnetic polarizations. Coupling of these polarizations is potentially useful for energy-efficient information storage and processing. Hexagonal rare-earth ferrites (h-RFeO₃, where R is rare-earth element and Fe is iron) are new family of multiferroic materials. Magnetic interactions between rare-earth and iron ions in h-RFeO₃, may amplify the weak ferromagnetic moment of iron, making these materials more appealing as multiferroics. Using element-specific magnetic characterization techniques, Nebraska MRSEC researchers have elucidated the nature of the interaction between the rare-earth ion, ytterbium (Yb), and the iron ion, in multiferroic h-YbFeO₃. Their results directly reveal anti-alignment of the magnetic moments of ytterbium and iron at low temperature, known as a ferrimagnetic order. These findings suggest an important role which is played by the rare-earth ions in tuning the multiferroic properties of hexagonal ferrites (S. Cao et al, Phys. Rev. B 95, 224428 (2017)).

This research is supported by the National Science Foundation, Division of Materials Research, Materials Research Science and Engineering Program, Grant DMR-1420645. 

Magnetic structure of hexagonal ytterbium ferrite (h-YbFeO₃) in which iron (Fe) magnetic moments (indicated by blue arrows) are anti-aligned to ytterbium (Yb) magnetic moments (indicated by grey arrows), thus revealing ferrimagnetism of multiferroic hexagonal ferrite h-YbFeO₃.