Variable Temperature Scanning Hail Probe Microscopy (SHPM) Using Quartz Crystal AFM Feedback

摘要

Scanning Hall Probe Microscopy (SHPM)[1] is a quantitative and non-invasive technique for imaging localized surface magnetic field fluctuations such as ferromagnetic domains with high spatial and magnetic field resolution of ～50nm [2] and 7mG/√Hz at room temperature. In the SHPM technique, Scanning Tunneling Microscope (STM) [1] or Atomic Force Microscope (AFM)[3] feedback is used to keep the Hall sensor in close proximity of the sample. However, STM tracking SHPM requires conductive samples; therefore the insulating substrates have to be coated with a thin layer of gold. This constraint can be eliminated with the AFM feedback using sophisticated Hall probes that are integrated with AFM cantilevers. However it is very difficult to micro fabricate these sensors. In this work, we have eliminated the difficulty in the cantilever-Hall probe integration process, just by gluing a Hall Probe chip to a quartz crystal tuning fork force sensor. The resultant SHPM can operate in variable temperature environment, 77-300K.