Formation Kinetics and Cation Inversion in Mechanically Activated MgAl₂O₄ Spinel Ceramics
Solid-state mechanical activation of MgO and α-Al2O3 powders was used to produce MgAl2O4. The cation site occupancy in the resulting MgAl2O4 spinel was investigated using different methods. Differential thermal analysis and thermal gravimetry showed that mechanical activation reduced the spinel formation temperature by around 200°C, and the corresponding activation energy by about 25%. In addition, characteristic temperatures for evaporation of physisorbed water and decomposition of Mg(OH)2 shifted to lower values, and peaks were more pronounced. Raman spectra were used to characterize the degree of inversion as a function of the sintering temperature for all of the sintered specimens, indicating that the breaking point for ordering of the crystal structure was around 1500°C for non-activated samples, and 1400°C for activated samples.
N. Obradovic et al., "Formation Kinetics and Cation Inversion in Mechanically Activated MgAl₂O₄ Spinel Ceramics," Journal of Thermal Analysis and Calorimetry, Springer Netherlands, Sep 2019.
The definitive version is available at https://doi.org/10.1007/s10973-019-08846-w
Materials Science and Engineering
Keywords and Phrases
DTA; Mechanical Activation; Raman Spectroscopy; Sintering Kinetics; Spinel
International Standard Serial Number (ISSN)
Article - Journal
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01 Sep 2019