We present the development of a new 4-lead hall gradiometer and a novel method
to measure 3 components( Bx, By & Bz) of magnetic fields on specimen
surfaces with submicron resolution using Scanning Hall probe Microscope [1]
and gradiometer. We used a 1µm size P-HEMT Hall sensor, operated in
gradiometer configuration to image Bx, By and Bz distribution of a hard disk
sample surface at 77K. The SHPM was used in Quartz Crystal AFM tracking mode
[2]. This simple and quick novel method shows ~40x better spatial
resolution compared to previously developed techniques [3] and can be
improved even further, down to sub 50nm resolution.