Scanning vector Hall probe microscope

Abstract

We present a scanning vector Hall probe microscope for imaging the entire magnetic field vector in close proximity to magnetic and superconducting samples. The microscope combines a large scanned area and a high space resolution of the magnetic field vector measured. A special feature of the equipment is a vacuum-tight sample space connected with a moving system via a flexible metal bellows. The microscope is based on a vector Hall sensor that consists of three separate Hall probes of an active area 5×5 μm2, patterned on three sides of a GaAs pyramid. The top of the pyramid serves as a tunneling contact and helps to control the sensor–sample separation. The sensor and the sample are placed in a helium cryostat with a temperature control in the range 10–300 K. The sensor scans an area up to 5×5 mm2 in the whole temperature interval with a spatial resolution ∼5 μm.