Systematic study of magnetic tip induced magnetization reversal of e-beam patterned permalloy particles

Patterned nanoscale permalloy particles, with different aspect ratios and widths, were studied by magnetic force microscopy in different operating modes with various magnetic tips. The stray field from the magnetic tip itself could reverse the particle moment orientation while acquiring topography data or when the tip is very close to the sample. Model calculations show that in most cases the stray field from the tip is big enough to reverse the particle’s moment. To reduce the tip’s influence, one should be very careful in choosing the magnetic tip coating and the operating mode of the microscope. Control of the magnetic state of an individual particle is demonstrated.