NUST MISIS employees found that the decrease in magnetic characteristics in a promising alloy based on manganese, aluminum, and gallium is associated with defects in its internal structure. These defects reduce the magnetization of the material by approximately 10%. The results obtained will help develop new approaches to creating more powerful and affordable permanent magnets for energy, transport, and the electronics industry.
Permanent magnets are used in electric motors, generators, sensors, and other devices. Today, rare earth materials provide the best characteristics, but their production is expensive and depends on limited resources. Therefore, alternatives based on available metals are actively being sought worldwide. One promising candidate is an alloy of manganese, aluminum, and gallium, which can maintain strong magnetic properties without the use of rare earth elements. However, in practice, its characteristics often turn out to be lower than calculated.
MISIS researchers studied a rapidly quenched Mn-Al-Ga alloy using transmission electron microscopy and atomic-level computer modeling. The analysis showed that a large number of linear crystal lattice defects form inside the material. These defects create boundaries between crystal regions where the original order of atom arrangement is disrupted.
Scientists found that it is near these boundaries that an antiferromagnetic bond arises between manganese atoms. As a result, some atoms compensate for each other's magnetic action, which leads to a decrease in the overall magnetization of the material. Such defects can reduce saturation magnetization by approximately 10%. Researchers have for the first time managed to directly link the features of the internal structure of the alloy with the deterioration of its magnetic properties.
MISIS noted that understanding this mechanism allows for targeted searches for ways to reduce the number of defects or prevent their formation already at the alloy production stage. The research results open up new opportunities for improving manganese-based magnetic materials. In the future, this will make it possible to create more efficient and affordable magnets for energy, transport, and the electronics industry without using scarce rare earth elements.
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