Demonstration of magnetic field imaging in a permalloy film with neutron spin phase contrast imaging

Recently, the neutron spin phase contrast (NSPC) imaging technique was performed using a neutron spin interferometer (NSI). An NSI enables us to measure the Larmor-precession of the neutron spin caused by the magnetic field in a magnetic object and provides magnetic field images in the object. We tried to visualize the magnetic field in a permalloy film with a varying external stress using an NSPC, for which the decay of the saturation magnetic field and the increment of the leak field with increasing stress were observed.