New two-dimensional homogeneous bias device induced under moderate pressure

Magnetic transition of Fe3GeTe2 induced by uniaxial compression, magneto-optic phenomenon of Fe₃gete₂ after compression and Fe exchange polarization effect₃gete₂ non-aging, expandable and recoverable. 1 credit

In a study published in Advanced materialsResearchers from the Hefei Institutes of Physical Sciences of the Chinese Academy of Sciences, in cooperation with researchers from the University of Science and Technology of China, have developed a new type of moderate pressure two-dimensional homogeneous bias device.

Compared to similar three-dimensional devices, the two-dimensional bias device has been described as “non-aging, expandable, and recoverable.”

“This provides a new idea for the design of low-dimensional magnetic devices and the study of the mechanism of the exchange bias effect,” said Sheng Zhigao, who led the team, “and we expect that that it will become the central magnetic component of two-dimensional electronics technology and equipment.”

Van der Waals two-dimensional magnetic materials provide an excellent platform for basic magnetic research and the development of low-dimensional magnetic devices due to their layered structure, lack of dangling bonding surface, and strong anisotropy. magnetic. However, the weak interlayer coupling greatly limits the application of two-dimensional magnetic material functional devices. Therefore, how to efficiently achieve strong magnetic exchange through interface engineering has become one of the key issues in building two-dimensional magnetic devices.

In this study, the researchers experimented with many materials and technical methods. They found that the two-dimensional germanium iron tellurium (Fe₃gete₂) a ferromagnetic ground-state material can be induced into a homogeneous, magnetic heterostructure with ferromagnetic-antiferromagnetic coexistence by uniaxial pressure technology.

At the same time, they discovered that the structure has a practical trade-bias effect.

This pressure-induced phase transition has been confirmed by magneto-optical tests, high-resolution transmission electron microscopy, and first-principles calculations.

Since the ferromagnetic-antiferromagnetic coupling of the homogeneous and magnetic heterostructure of the material occurs inside the homogeneous junction, its exchange polarization effect exhibited excellent characteristics due to the atomically smooth magnetic interface.

“These features (non-aging, stretchable and rechargeable) cannot be found in three-dimensional devices,” said team member Hou De.

The results open a new avenue for the design and development of high-performance two-dimensional magnetic devices, and their excellent exchange bias characteristics provide an opportunity for the efficient application of two-dimensional magnetic devices.