Accession Number : AD0718829

Title :   Semi-Conduction and Electron Hopping in Vitreous Systems: Magnetic Properties, Micro-Structure, and Ultra-Structure of Partially Crystallised B203-BaO-Fe203 Glass.

Descriptive Note : Annual technical rept. no. 2, 1 Jan 70-1 Jan 71,

Corporate Author : RENSSELAER POLYTECHNIC INST TROY N Y DIV OF MATERIALS ENGINEERING

Personal Author(s) : Fahmy,Mohammed ; Park,Mann J. ; Tomozawa,Minoru ; MacCrone,Robert K.

Report Date : JAN 1971

Pagination or Media Count : 43

Abstract : The crystallisation products and morphology of a 68B2O3 - 17 BaO - 15 Fe2O3 mole % glass have been studied using magnetisation measurements, small angle x-ray scattering measurements and replica electron microscopy. The glasses containing the crystallised phases were super-paramagnetic down to 77 degrees K, and the magnetisation curves are analysed in terms of a bimodal distribution of magnetic moments. The SAXS and electron micrographs confirmed the bimodal distribution of particle sizes, and a very precise correlation between magnetic properties and microstructure is obtained. By quantitative calculations, it is shown that the precipitate phases themselves are complex in structure, and most likely consist of an inner ferrimagnetic core surrounded by an anti-ferromagnetic grape-fruit skin. This structure for the precipitates is confirmed directly by electron microscope observations. (Author)

Descriptors :   (*SEMICONDUCTORS, MAGNETIC PROPERTIES), (*GLASS, MICROSTRUCTURE), IRON OXIDES, BARIUM COMPOUNDS, BORON COMPOUNDS, OXIDES, ELECTRON MICROSCOPY, X RAY DIFFRACTION, HEAT TREATMENT, PHASE STUDIES, ANTIFERROMAGNETISM

Subject Categories : Ceramics, Refractories and Glass
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE