Auto ignition synthesis of nanocrystalline MgAl sub 2 O sub 4 and related nanocomposites

Nanocrystalline powders of various compositions in the Al sub 2 O sub 3 -MgO binary system were synthesized using a novel "auto ignition" process. the respective nitrates were used as starting materials and urea as fuel. Thermodynamic calculations of the adiabatic temperatures were perform...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials research 1999-09, Vol.14 (9), p.3571-3580
Main Authors: Bhaduri, S, Bhaduri, S B, Prisbrey, K A
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Nanocrystalline powders of various compositions in the Al sub 2 O sub 3 -MgO binary system were synthesized using a novel "auto ignition" process. the respective nitrates were used as starting materials and urea as fuel. Thermodynamic calculations of the adiabatic temperatures were performed for various compositions from Al sub 2 O sub 3 -rich to the MgO-rich side of the phase diagram. The combustion temperatures of the different compositions were also determined experimentally. The as-synthesized powders were characterized by x-ray diffraction (XRD0 and transmission electron microscopy (TEM). As a result of processing, spinel, alumina, magnesia, and solid solutions/nanocomposites thereof formed. Grain sizes and the lattice parameter were calculated based on XRD results. Where appropriate, the lattice parameter vs. the composition of these solid solutions satisfied Vegard's law. Spinel grains were in the 13-20 nm range, alumina grains were 30-40 nm, and MgO grains were 2-28 nm. The grain sizes calculated from XRD results were in good agreement with the TEM results.
ISSN:0884-2914