Abstract
Gel combustion synthesis was investigated on rare earth aluminates, especially gadolinium aluminate, by adjusting Gd/Al ratios in mixed nitrate aqueous solution and the kinds of fuel. Use of urea as the fuel was essential to obtain the crystallized oxides as the combustion products in any Gd/Al compositions although glycine fuel gave amorphous products in their aluminum-rich composition. FT-IR measurements showed that urea molecules coordinated to both aluminum and gadolinium ions, but that glycine molecules only to the latter to form their coordination polymer. The coordination polymer contributes not only to obtain homogeneously mixed gel in the starting material but also to the explosive combustion leading to high temperature reaction.
