Accession Number:

AD0417179

Title:

ON THE MAGNETIC PROPERTIES OF PIEZOELECTRIC GALLIUM-IRON OXIDE,

Descriptive Note:

Corporate Author:

HARVARD UNIV CAMBRIDGE MASS CRUFT LAB

Personal Author(s):

• Nowlin,Charles H.

Report Date:

1963-04-30

Pagination or Media Count:

1.0

Abstract:

This study of the magnetic properties of oxide systems was undertaken primarily in order to understand better the magnetic structure and the probable source of the anisotropic behavior of piezoelectric, ferromagnetic gallium iron oxide. A vibrating-sample magnetometer with a sensitiv ity of 3 x 10 to the -5th power erggauss was constructed, in order to measure the magnetic moments of the various oxides. The basic mag netometer design of Foner was followed, but some important modifications were added. Changes were made in the cryogenic system in order to bring a previously erratic temperature behavior under control. The electronic system used incorporates two novel features. The first of these is the use of an A.C. servomotor and flywheel as an electromechanical phase-sensitive detector to in dicate the nulls of the A.C. potentiometer. The response of this null detector is much faster than conventional electronic circuits having the same noise-discrimination. The second feature is a new, simplified twin-T frequency-selective amplifier. Author

Descriptors:

• PIEZOELECTRIC CRYSTALS
• PIEZOELECTRIC CRYSTALS
• OXIDES
• CRYOGENICS
• GARNET
• LOW FREQUENCY
• PHASE SHIFT CIRCUITS

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE