Browse Prior Art Database

Vibrating Sample Magnetometer

IP.com Disclosure Number: IPCOM000075809D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Berry, BS: AUTHOR [+2]

Abstract

Apparatus is provided for determining the magnetization, hysteresis and other properties of ferromagnetic samples in the form of strips.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 85% of the total text.

Page 1 of 2

Vibrating Sample Magnetometer

Apparatus is provided for determining the magnetization, hysteresis and other properties of ferromagnetic samples in the form of strips.

Relative motion is obtained between the specimen and the pickup coils. The present arrangement is a vibrating sample magnetometer, in which the strip is excited into a natural mode of transverse vibration as the means of obtaining motion with respect to the pickup coils.

The instrument is sketched in the figure. The specimen, clamped at one end as a cantilever, is excited into flexural vibration (at the fundamental mode) by a standard type of polarized electrostatic drive. The amplitude of vibration may be monitored either optically (with a measuring microscope) or by an electrical pickup. In the figure, a second pair of electrodes is positioned around the sample to provide a capacitance pickup arrangement with which to supplement optical observations. When the specimen is magnetized, the motion of the free end of the sample includes an alternating voltage signal in the pickup coil. The signal amplitude e(o) is given by e(o) = C f y(o) A I where C is a coil geometry constant, f is the frequency of vibration, y(o) is the amplitude of vibration, A is the cross- sectional area of the sample, and I is its intensity of magnetization. Calibration of the apparatus to find C is easily performed by saturating a sample of known saturation intensity I(s). Illustrative applications of this apparatus are:

a) To...