  Chiral molecules have the potential for creating new magnetic devices by
locally manipulating the magnetic properties of metallic surfaces. When chiral
polypeptides chemisorb onto ferromagnets they can induce magnetization locally
by spin exchange interactions. However, direct imaging of surface magnetization
changes induced by chiral molecules was not previously realized. Here, we use
Magneto-optical Kerr microscopy to image domains in thin films and show that
chiral polypeptides strongly pin domains, increasing the coercive field
locally. In our study, we also observe a rotation of the easy magnetic axis
towards the out-of-plane, depending on the sample's domain size and the
adsorption area. These findings show the potential of chiral molecules to
control and manipulate magnetization and open new avenues for future research
on the relationship between chirality and magnetization.
