Accession Number : AD0623530

Title :   RESEARCH TO INVESTIGATE THE MICROSTRUCTURE OF THE INTERNAL MAGNETIC FIELD IN SELECTED MAGNETIC MATERIALS.

Descriptive Note : Final rept. for 10 Feb 64-10 Aug 65,

Corporate Author : GENERAL ELECTRIC RESEARCH LAB SCHENECTADY N Y METALLURGY AND CERAMICS RESEARCH DEPT

Personal Author(s) : Graham,C. D. ,Jr. ; Becker,J. J. ; Jacobs,I. S.

Report Date : SEP 1965

Pagination or Media Count : 75

Abstract : The magnetization of a gadolinium single crystal has been measured over a range of fields and temperatures. Magnetic measurements were made on Fe(2-X)Ge and Fe2B. A relatively simple vibrating-sample magnetometer has been constructed for use in this program. A variety of experimental and theoretical work has been carried out on selected antiferromagnetic compounds. The low-temperature parallel susceptibilities of FeF2 and Cr2O3 have been accounted for by the single-ion Van Vleck susceptibility mechanism, thus obviating the need for explanations based on canted spin structures or crystal imperfections. The compounds EuTe and CoC12 have been shown to have nonlinear transverse susceptibilities, and this effect has been shown to arise primarily from the field-dependence of the zero-point spin wave contribution to the free energy. Careful measurements of the magnetization of metamagnetic FeC12 have been made. Hysteresis has been observed in the metamagnetic transitions of FeC12 and FeBr2, and analysis of this problem leads to the conclusion that hysteretic behavior should be expected in all transitions of this type at least under ideal conditions. The high-field measurements on CoC12 showed an anomalously high saturation moment per Co(2+) ion, and this has been explained by an exchange-enhanced g-shift.

Descriptors :   (*MAGNETIC MATERIALS, MAGNETIC PROPERTIES), (*GADOLINIUM, MAGNETIC PROPERTIES), (*FERROMAGNETIC MATERIALS, MAGNETIC PROPERTIES), (*ANTIFERROMAGNETISM, MAGNETIC MATERIALS), SINGLE CRYSTALS, RARE EARTH ELEMENTS, ANISOTROPY, IRON ALLOYS, BORON ALLOYS, GERMANIUM ALLOYS, EUROPIUM COMPOUNDS, TELLURIUM ALLOYS, COBALT COMPOUNDS, IRON COMPOUNDS, CHLORIDES, HYSTERESIS, INTERMETALLIC COMPOUNDS, MICROSTRUCTURE, CRYSTAL DEFECTS

Distribution Statement : APPROVED FOR PUBLIC RELEASE