Characterization of high density spin valve recording heads by novel magnetic force microscope

High area density magnetic recording heads with giant-magnetoresistance (GMR) read sensors and focus-ion-beam (FIB) trimmed inductive writers were studied with a special magnetic force microscope (MFM). The MFM was equipped with a magnetoresistance sensitivity mapping (MSM) component that directly measures the magnetoresistance of the reader sensor as a function of position, and a High Frequency MFM (HFMFM) capability that maps 3D high frequency writing field distribution. Good agreement between the MSM measurement and the spin stand tests were obtained. MFM measurement offers unique high spatial resolutions not readily achievable with any other measurement techniques. It is the ideal tool for current and future high area density heads.