Browse Prior Art Database

Particle Detection by Magnetic Resonance

IP.com Disclosure Number: IPCOM000040799D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Agopian, GK: AUTHOR [+2]

Abstract

Many types of magnets are used in data storage where the magnets are coated with an organic coating (paint) to encapsulate the magnetic particles. An inspection is needed to determine whether the coated magnet surfaces are free of magnetic or magnetizable particles. The presence of such particles could cause erasure of information in addition to mechanical damage.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Particle Detection by Magnetic Resonance

Many types of magnets are used in data storage where the magnets are coated with an organic coating (paint) to encapsulate the magnetic particles. An inspection is needed to determine whether the coated magnet surfaces are free of magnetic or magnetizable particles. The presence of such particles could cause erasure of information in addition to mechanical damage.

Magnetic particles can be detected by placing them in a homogeneous field and looking for changes in field homogeneity. An NMR spectrometer (nuclear magnetic resonance), normally used for the identification of organic compounds, can be used to detect magnetic particles suspended in a suitable solvent (such as deuterated acetone). The process is run as follows: suspend particle(s) in the solvent in an NMR tube and take an NMR Spectrum of the solvent. Several effects are looked at to detect the presence of magnetic particles: (1) field homogeneity, (2) magnetic susceptibility of the solvent, and (3) signal broadening.

Any of these three effects can be used to detect the presence (or absence) of magnetic particles when placed in the presence of a strong, homogeneous magnetic field.

The NMR technique can be applied to detect the presence of magnetic and magnetizable particles in a very fast way not possible by other techniques. The technique can be used to inspect coated magnets or other parts for the absence of magnetic/magnetizable particles.

Disclosed anonymously...