What the study found
Mn3NiN changes from a ferrimagnetic state to a non-collinear antiferromagnetic state with a disordered, dendritic magnetic domain structure. The domain roughness increases on cooling and reaches a fractal dimension of about 1.55 in the non-collinear phase.
Why the authors say this matters
The authors say that controlling magnetic domain states is critical for using unconventional magnets in quantum spintronics and hybrid quantum devices, because their symmetry-driven properties vanish when many domains are present. The study suggests that understanding how domains form in materials with compensated local moments is important for explaining and controlling these materials.
What the researchers tested
The researchers examined the ferrimagnetic-to-non-collinear antiferromagnetic phase transition of Mn3NiN using scanning nitrogen-vacancy centre magnetometry, a method that maps magnetic fields at nanoscale resolution with a diamond defect called a nitrogen-vacancy centre. They correlated local stray fields with global magnetometry and anomalous Hall effect measurements.
What worked and what didn't
The nanoscale measurements revealed a disordered, dendritic domain pattern, and the fractal dimension steadily increased during cooling through the transition. However, the domain area distribution did not show significant changes. The authors report that the observed behavior cannot be explained by the balance of demagnetisation energy and domain wall energy.
What to keep in mind
The abstract does not describe detailed experimental limits beyond the scope of the Mn3NiN phase transition studied here. The authors conclude that elastic contributions and defects are a critical factor to explain the domain size, but the abstract does not provide further detail on how these were tested.
Key points
- Mn3NiN was observed to form a disordered, dendritic magnetic domain structure on cooling.
- The domain roughness increased through the transition and saturated at a fractal dimension of about 1.55.
- The domain area distribution did not show significant changes.
- The observed behavior was not explained by demagnetisation energy and domain wall energy alone.
- The authors conclude that elastic contributions and defects are critical factors in explaining domain size.
Disclosure
- Research title:
- Domain roughness grows across Mn3NiN phase transition
- Authors:
- Freya Johnson, Jan Zemen, Helena S. Knowles, L. F. Cohen
- Institutions:
- Bridge University, Czech Technical University in Prague, Imperial College London
- Publication date:
- 2026-04-24
- OpenAlex record:
- View
- Image credit:
- Photo by Ayush Kumar on Unsplash · Unsplash License
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