Abstract:
A research team at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) announced that they have discovered a new way to control magnetism without changing the chemical composition of the material. Research has shown that by applying only slight mechanical strain, it is possible to change the magnetic structure inside some crystalline materials and further affect their electron transport properties. This discovery is expected to open up new technological paths for the development of next-generation spintronics devices.
Researchers have focused on a new type of magnetic material called "alternating magnets". This type of material has become an important direction in the research of advanced electronic devices in recent years due to its unique magnetic properties and electronic characteristics. The research team used neutron beams to observe materials from the atomic scale and found that mechanical strain can readjust the magnetic order structure in the material and change the electrical response related to electron transport.
Relevant research results were published in two academic journals, "Physical Review X" and "Advanced Materials". The findings suggest that physically applying stress to materials may be a new way to control magnetism in the future, without the need to dope or change the material's chemical composition to adjust properties.
During the experiment, the researchers sandwiched tiny crystals of manganese telluride and iron sulfide between two titanium plates and applied mechanical pressure. They then used the neutron beam produced by the spallation neutron source at Oak Ridge National Laboratory to conduct neutron diffraction experiments to study the effect of strain on the internal magnetic domain structure of the material.
Experimental results show that slight squeezing changes the relative proportions occupied by different magnetic domains. Magnetic domains are areas with different magnetic ordering directions within the material, and changes in their distribution will directly affect the overall magnetic performance of the material. At the same time, the research team also observed changes in the anomalous Hall effect. This electrical phenomenon produces a voltage perpendicular to the direction of current flow, and its changes illustrate a direct link between the adjustment of the magnetic structure and the behavior of electron transport. Dai Pengcheng, a professor at Rice University and a former neutron scientist at Oak Ridge National Laboratory, said that by controlling the magnetic domain structure, researchers can directly affect the electron transport properties of the material, which creates new possibilities for exploring the application of related materials in the field of spintronics.
Alternating magnets have attracted much attention because their special magnetic properties combine some of the advantages of traditional ferromagnets and antiferromagnets. Spintronics technology hopes to use not only the charge information carried by electrons, but also the spin of electrons to complete information storage and processing tasks. This method is expected to achieve higher speed and lower energy consumption information processing mode than traditional electronic technology.
The research team pointed out that this discovery established a direct connection between mechanical strain, magnetic domain structure and electron transport behavior, proving that the magnetic and electrical properties of materials can be adjusted through simple physical deformation. If relevant technologies can be further improved in the future, it may promote the development of new low-power memories, high-performance computing equipment and advanced spin electronic devices.
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