Synthesis　of　Whisker-Like　MgAl204 Spinel　from　Gibbsite　and　Magnesium　Acetate

Abstract

Whisker-like　boehmite　crystals　with　high　aspect　ratios　were　hydrothermally　synthesized　from gibbsite　in　magnesium　acetate （Mg（CH3COO）2；MgAc2） solution，and　they　were　used　as　a component　of　a　precursor　of　MgAl204 spinel． The　precursor　of　the　spinel　was　a　mixture　of　Mg-doped　boehmite，MgAc2 deposited　on　boehmite and　small quantities　of　unknown　compounds．The　precursor　was　heated　at 500-1200℃ for　1h　in　air． The　spinel　was　formed　lust　after　the　decomposition　of　MgAc2 into　activated　MgO　by　the　reaction between　the　boehmite　and　the　MgO　without　accompanying　the　formation　of γ-Alumina　phase．The spinel　formation　occurred　at　a　temperature　as　low　as 500℃ in　air．