Researchers have created a metal–organic framework (MOF) that exhibits strong magnetism while producing no external magnetic field. This effect arises from the internal magnetic moments within the MOF that align in opposite directions, effectively neutralizing each other. Consequently, the material emits very little magnetic “noise,” making it a promising option for more energy-efficient electronics.
Historically, strongly magnetic substances generate stray fields that can disrupt or demagnetize adjacent magnets, creating issues for their use in spintronics. Spintronics utilizes both the charge and spin of electrons for data processing, but it necessitates materials that produce minimal external magnetic fields, or compensated ferrimagnets, to operate effectively. Nonetheless, such materials usually only exhibit their desirable characteristics at low temperatures.
The innovative MOF maintains a nearly zero external magnetic field over a wide temperature range. It is composed of chromium(III) ions coordinated with planar pyrazine molecules in a cubic, perovskite-like framework, where the pyrazine linkers act as radicals due to having an unpaired electron. The opposing orientations of magnetic moments from the chromium cations and pyrazine linkers, in contrast to those resulting from their interactions, result in mutual cancellation.
Testing has shown that this MOF’s external magnetic field remains minimal and stable between 3 and 300K, indicating its potential for various room-temperature electronic and spintronic applications.