Observation of Uniaxial Strain Tuned Spin Cycloid in a Freestanding BiFeO₃ Film

Bismuth ferrite (BiFeO3) possesses a non-collinear spin order while the ferroelectric breaks space inversion symmetry. This allows efficient electric-field control of magnetism and makes it promising candidate for applications in low-power spintronic devices. Epitaxial strain effects have been intensively studied exhibit significant modulation magnetic bismuthBiFeO3, but tuning its structure with continuously varied uniaxial is still lacking at this moment. Herein, situ tensile applied to freestanding BiFeO3 film by mechanically stretching an organic substrate. A scanning nitrogen-vacancy (NV) microscopy image nanoscale real space. The increased from 0% 1.5% four images under different strains are acquired during period. show that cycloid tilts ≈12.6° when approaches 1.5%. first principle calculation processed tilting energetically favorable such strain. applying method combination NV microscope real-space imaging ability paves new way studying coupling between films.