Chirality Switching Of An Antiferromagnetic Spiral Wall And Its Effect On Magnetic Anisotropy

An antiferromagnetic NiO spiral wall in Fe/NiO/Co0.5Ni0.5O/vicinal Ag(001) was created by rotating Fe magnetization and investigated using x-ray magnetic linear dichroism (XMLD). Different from the Mauri's 180 degrees spiral wall, we find that the NiO spiral wall always switches its chirality at similar to 90. rotation of the Fe magnetization, and unwinds the spiral wall back to a single domain with a further rotation of the Fe magnetization from 90 degrees to 180 degrees. The effect of this chirality switching on themagnetic anisotropy was studied using rotationalmagneto-optic Kerr effect (ROTMOKE) on Py/NiO/Co0.5Ni0.5O/vicinal Ag(001). We find that the original Mauri's model has to be corrected by an energy folding due to the chirality switching, which consequently converts the exchange bias from the Mauri's 180 degrees spiral wall into a uniaxial anisotropy and a negative fourfold anisotropy.