Kyoto, Japan -- Close to a phase transition, very different materials can follow the same mathematical rules. The concept of universality, which groups seemingly distinct systems based on their common properties, was developed to describe this phenomenon. In magnetic systems, ferromagnets, ferrimagnets, and antiferromagnets fall into the same universality class when short-range interactions dominate and their spatial and spin dimensionalities coincide. However, this universality has not been established when long-range interactions dominate.

In insulating magnets, long-range coupling may originate from dipole-dipole interactions. However, dipolar-driven mean-field criticality has only been firmly established in ferromagnets, leaving the ferrimagnetic and antiferromagnetic cases unexplored. A collaborative team of researchers from Kyoto University, Tohoku University, and the Australian Nuclear Science and Technology Organisation (ANSTO), set out to bridge this gap.

"Near a phase transition, the microscopically strongest interaction is not always the one that sets the critical rules," explains corresponding author Yusuke Nambu. "Exchange interactions build the ferrimagnetic state, but because dipolar interactions reach much farther, they determine how the material approaches the transition."

M. Parans Paranthaman, an expert in solid-state chemistry and materials science at the Department of Energy’s Oak Ridge National Laboratory, has been named R&D World’s 2026 Researcher of the Year. The honor recognizes his career translating fundamental materials research into practical technologies with real-world applications. Paranthaman, an ORNL Corporate Fellow and UT-Battelle Distinguished Inventor, joined ORNL in 1993. He has authored more than 500 peer-reviewed publications and possesses 65 U.S. patents.