Bismuth nano-Hall probes fabricated by focusedion beam millingfor directmagnetic imaging by room temperature scanning Hall probe microscopy

Bismuth nano-Hall probes with dimensions ~120 × 120 nm were fabricated by focused ion beam milling and used for the direct room temperature magnetic imaging of crystalline garnet thin films and strontium ferrite permanent magnets by scanning Hall probe microscopy. At driving currents of 40 µA, the Hall coefficient and magnetic field sensitivity of the Bi nano-Hall probes were 3.3 × 10-4 Ω/G and 7.2 G/√Hz, respectively.