Size effect and order–disorder phase transition in MgAl2O4: synthesized by co-precipitation method
- 129 Downloads
We report on the size effect and order–disorder phase transitions in MgAl2O4 system synthesized by chemical co-precipitation method. The prepared samples were sintered at various temperatures (in steps of 200 °C). Initially, the order–disorder phase evolution of the cubic spinel aluminates were analyzed by powder X-ray diffraction and UV-absorbance spectral analysis. The optical band gap was calculated from UV–DRS absorbance spectra. Also, the grain size of the sintered aluminates was calculated by high resolution scanning electron microscopy through surface morphological image analysis and discussed. Moreover, the particle size was calculated by using transmission electron microscopy. The stretching and bending mode of tetrahedral and octahedral coordinates for vibration modes of cations were studied through Fourier transform infrared spectral analysis. In addition, the cation distributions in the prepared samples were carried out by solid-state nuclear magnetic resonance spectroscopic measurement and analyses. The frequency dispersive behavior of dielectric constant was analyzed at room temperature for the synthesized samples using impedance analyzer. The observed results are discussed and reported.
It has been approved by all of the authors, and due care has been taken to ensure the integrity of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.C. Baudin, R. Martinez, P. Pena, High-temperature mechanical behavior of stoichiometric magnesium spinel. J. Am. Chem. Soc. 78(7), 1857–1862 (1995)Google Scholar
- 8.R. Maschio, B. Fabbri, C. Fiori, Industrial applications of refractories containing magnesium aluminate spinel. Ind. Ceram. 8, 121–126 (1988)Google Scholar
- 19.S. Nishikawa, Structure of some crystals of spinel group. Tokyo Sugaku-Buturigakkwai Kizi Dai 2 Ki 5(7), 199–209 (1915)Google Scholar
- 29.H.J. Jakobsen, J. Skibted, H. Bildsbe, N.C. Andniels, Magic-angle spinning NMR spectra of satellite transitions for quadru-polar nuclei in solids. J. Magn. Reson. 85, 173–180 (1989)Google Scholar
- 31.B.J. Wood, R.J. Kirkpatrick, B. Montez, Order-disorder phenomena in MgAl2O4 spinel. Am. Mineral. 71, 999–1006 (1986)Google Scholar
- 38.J.I. Pankove, Optical Process in Semiconductor (Dover publications, Inc., New York, 1971)Google Scholar
- 40.M. Fox, Optical Properties of Solids. (Oxford University press, Oxford, 2001)Google Scholar
- 43.J. Preudhomnei, P. Taiwe, Infra-red studies of spinels-III. The normal II-III spinel. Spectrochim. Acta 27A, 1817–1822 (1970)Google Scholar
- 44.J. Preudhomnei, P. Tarte, Infrared studies of spinel-I: a critical discussion of the actual interpretations. Spectrochim. Acta 27A, 961–968 (1970)Google Scholar
- 45.Siby Kurien, Structural and electrical properties of certain nanocrystalline aluminates, e-ThesisGoogle Scholar
- 52.S. Kurien, J. Mathew, S. Sebastian, K.C. George, Structural and electrical properties of nano-sized magnesium aluminate. Indian J. Pure Appl. Phys. 42, 926–933 (2004)Google Scholar