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Title: Structural transitions in alumina nanoparticles by heat treatment

γ-alumina nanoparticles were annealed sequentially at 800°C, 950°C and 1100°C and structural transitions as a function of heat treatment were studied by X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and {sup 27}Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) methods.. XRD studies found that γ-Al{sub 2}O{sub 3} is stable upto a temperature of at least 950°C and transforms to the thermodynamically stable α-phase after annealing at 1100°C. MAS-NMR revealed that γ-alumina contains AlO{sub 4} and AlO{sub 6} structural units in the ratio 1: 2, while α-phase contains only AlO{sub 6} units. DSC confirmed that γ → α transition initiates at 1060°C.
Authors:
;  [1] ;  [2] ;  [3]
  1. Glass Physics and Sensors Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar-143005, Punjab (India)
  2. Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL 32306-4390 (United States)
  3. Department of Chemistry and Process & Recourse Engineering, University of Cantabria, Santander-39005 (Spain)
Publication Date:
OSTI Identifier:
22606244
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1731; Journal Issue: 1; Conference: DAE solid state physics symposium 2015, Uttar Pradesh (India), 21-25 Dec 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM 27; ALUMINIUM OXIDES; ANNEALING; CALORIMETRY; CRYSTAL-PHASE TRANSFORMATIONS; HEAT; NANOPARTICLES; NUCLEAR MAGNETIC RESONANCE; TEMPERATURE RANGE 1000-4000 K; X RADIATION; X-RAY DIFFRACTION