Abstract
A bismuth micro-Hall probe sensor with an integrated scanning tunnelling microscope tip was incorporated into a room temperature scanning Hall probe microscope system and successfully used for the direct magnetic imaging of microscopic domains of low coercivity perpendicular garnet thin films and demagnetized strontium ferrite permanent magnets. At a driving current of 800 µA, the Hall coefficient, magnetic field sensitivity and spatial resolution of the Bi probe were 3.3 ×10-4 Ω/G, 0.38 G/√Hz and ∼2.8 µm, respectively. The room temperature magnetic field sensitivity of the Bi probe was comparable to that of a semiconducting 1.2 µm GaAs/AlGaAs heterostructure micro-Hall probe, which exhibited a value of 0.41 G/√Hz at a maximum driving current of 2 µA.