Room temperature magnetic imaging of magnetic storage media and garnet epilayers in the presence of external magnetic fields using a sub-micron GaAs SHPM


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SANDHU A., MASUDA H., Oral A. , Bending S.

11th International Conference on Molecular Beam Epitaxy, Beijing, China, 11 - 15 September 2000, pp.899-905 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1016/s0022-0248(01)00925-3
  • City: Beijing
  • Country: China
  • Page Numbers: pp.899-905
  • Keywords: scanning hall probe microscope, magnetic fields, molecular beam epitaxy, magnetic materials, Hall effect sensor, heterojunction semiconductor devices, HALL PROBE MICROSCOPY

Abstract

A multipurpose room temperature scanning Hall probe microscope (RT-SHPM) system incorporating an ultra-high sensitive sub-micron GaAs Hall probe (active area of similar to0.8 x 0.8 mum(2) room temperature Hall coefficient of 0.3 Ohm /G) exhibiting extremely high magnetic field sensitivity (0.04G/root Hz) was used for the direct, non-invasive and quantitative imaging of magnetic field fluctuations in very close proximity to the surfaces of thin film magnetic storage media, Bi substituted iron garnet epilayers and demagnetized Sr-ferrite permanent magnets placed in external magnetic fields. A scanning tunnelling microscope tip integrated adjacent to the Hall probe was used for precise vertical positioning of the probe. RT-SHPM images of 1.4 MB written floppy disks clearly showed well-defined magnetic transitions to coalesce into small island-like structures under external perpendicular fields greater than 1300 Oe. The RT-SHPM is demonstrated to be a versatile means of quantitatively monitoring micron-sized magnetic domain structures in the presence of external magnetic fields at: room temperature. (C) 2001 Elsevier Science B.V. All rights reserved.