US 5,900,728 A · Alternating current magnetic force microscopy system with probe having integrated coil

Abstract

An alternating current (AC) magnetic force microscopy (MFM) system incorporates an improved probe with an integrated coil on the free end of the system's cantilever. The probe has a pair of magnetic poles that form part of a magnetic yoke and a patterned electrically conductive coil wound through the yoke. The probe includes a probe tip that has a magnetic surface layer that is magnetically coupled to one of the poles and extends from it. When alternating current from the AC-MFM system is passed through the probe coil the magnetization direction of the probe tip correspondingly alternates. The interaction of these alternating magnetic fields from the probe tip with the magnetic fields emanating from the sample whose magnetic fields are to be measured causes the cantilever to deflect between two extreme positions. The probe can be formed from a portion of a disk drive air-bearing slider with a patterned thin film inductive write head on its trailing end by growing the probe tip from the slider's air-bearing surface so as to be in contact with the gap and one of the poles of the write head. The probe can also be part of an integrated single-piece structure that includes the cantilever, probe body and probe tip which are formed using conventional thin film deposition and lithographic processes.

Claims16

Dependent claims

An alternating current type of magnetic force microscopy system for scanning the surface of a magnetic sample, the system comprising:

a sample holder;
a flexible cantilever;
a probe attached to the free end of the cantilever, the probe comprising a probe body, a pair of magnetic poles formed on the body, a layer of electrically conductive material formed on the body and patterned as a coil between the poles, and a probe tip attached to an end of one of the poles, the probe tip having a surface of magnetic material;
a source of alternating electrical current electrically connected to the probe coil for generating an alternating magnetic field at the probe tip;
a scanning stage for moving the sample holder relative to the probe tip, whereby the probe tip may scan various locations on the surface of the magnetic sample held by the sample holder;
and
a cantilever deflection detector for generating a signal representative of the magnetic field from a location on the surface of the magnetic sample, the interaction of the magnetic field from the magnetic sample and the alternating magnetic field at the probe tip causing the cantilever to deflect in opposite directions.

4 more elements

Dependencies are inferred from the claim text.

Alternating current magnetic force microscopy system with probe having integrated coil

Life of this patent

Alternating current magnetic force microscopy system with probe having integrated coil

Life of this patent

Abstract

Claims16