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Low Temperature Processes for Production of Non-equilibrium Materials.
Messing-GL; Gardner-TJ; Roy-R
NTIS: PB/85-245173 :44 pages
The influence of salt precursor on the characteristics of mgo powders synthesized by the evaporative decomposition of solutions (eds) technique is presented. Thermal analysis results are used to determine the decomposition path for the mg(c2h3o2)2.4H20, mgcl2.6H20, mg(no3)2.6H2o, and mgso4 salts. Mgo powders with surface areas ranging from 30 to 150 m2/g have been prepared from the acetate and nitrate precursors. The decomposition of the chloride and sulfate precursors is incomplete during eds as a result of kinetic limitations imposed by the high heating rate (= 300 deg c/sec) associated with the eds process. Generally, the particle morphology consists of large aggretates for powders produced from the chloride, nitrate, and sulfate precursors. However, fine, dispersed submicrometer particles are formed from the acetate precursor. This difference is attributed to the fragmenting of the dried acetate salt aggregate during the exothermic decomposition of the acetate salt, whereas the dried salt aggregate structure persists for the other precursors, with strong mgo crystalline aggregates forming owing to localized sintering following salt decomposition. The thermal analysis results and the powder characteristics demonstate that these differences in particle morphology are a direct result of the decomposition path of the precursor salt.
CP; Final Contract Report;
NTIS Accession No.
Pennsylvania State Univ.
Page last reviewed: April 12, 2019
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