Submicron probes for Hall magnetometry over the extended temperature range from helium to room temperature

Abstract

We report on mesoscopic Hall sensors made from various materials and their suitability for accurate magnetization studies of submicron samples over a wide temperature range and, especially, at room temperature. Among the studied devices, the best stability and sensitivity have been found for Hall probes made from a high-concentration two-dimensional electron gas ͑HC-2DEG͒. Even at 300 K, such submicron probes can reliably resolve local changes in dc magnetic field of Ϸ1 G, which corresponds to a flux sensitivity of less than 0.1 0 ( 0 ϭh/e is the flux quantum͒. The resolution increases 100 times at temperatures below 80 K. It is also much higher for the detection of ac magnetic fields because resistance fluctuations limiting the low-frequency stability of the studied devices can be eliminated. Our second choice for room-temperature Hall micromagnetometry is gold Hall probes, which can show a sensitivity of the order of 10 G. The capabilities of HC-2DEG and gold micromagnetometers are demonstrated by measuring nm-scale movements of individual domain walls in a ferromagnet.

Decomposition of1/fNoise inAlxGa1−xAs/GaAsHall Devices

“…DOI High-mobility two-dimensional electron systems (2DES) in III/V semiconductor heterostructures such as n-Al x Ga 1ÿx As=GaAs are the subject of continuing interest in fundamental investigations, as, e.g., integer and fractional quantum Hall effect, as well as devices in electronic applications, such as high-speed modulation-doped field effect transistors, or high-sensitivity Hall magnetometers for noninvasive nanoscale magnetic measurements and biological sensing; see, e.g., Refs. [1][2][3] and references therein.…”

Direct measurement of the field from a magnetic recording head using an InAs Hall sensor on a contact write/read tester

“…The head is subsequently scanned using a nm-resolution piezoelectric stage with scan ranges from 10 to 100 mm. Similar sub-micron resolution measurement systems that have scanning capabilities [10] and that do not have scanning capabilities [11,12] have been previously demonstrated. Eliminating the media in the measurement process reduces the complexity of the measurement, allowing for a more direct measurement of MWW and a quantitative measurement of the magnetic field.…”

Optimal geometry of CMOS voltage-mode and current-mode vertical magnetic hall sensors

“…Hall sensors, with an active area of micron and submicron sizes, are fabricated from various metals (Au, Al) [5], alloys (NiFe) [6], (FePt) [7], semiconductors (InSb) [8], (InAs) [9], graphene [10] and carbon nanotubes [11]. Nevertheless, theses various types of materials are not compatible with high performance CMOS processes.…”