Bulk crystal growth of zinc aluminate spinel at room temperature

Abstract

Zinc aluminate ZnAl₂O₄ is a well known wide band gap compound semiconductor (E _g=3·8 eV) used in UV photoelectronic devices, antithermal coatings for spacecraft, and ceramic and catalyst materials. In the present work, the development of a single step process to synthesise and grow ZnAl₂O₄ spinel at low temperature is described. In this context, novel, economical and spontaneous growth of a bulk crystal of a ternary oxide material is reported. ZnAl₂O₄ crystals were grown at room temperature (30°C). Material to be grown as metal incorporated single crystals was taken as precursor and put into a neutral bath containing acid as reaction acceleration reagent (catalyst) as well as solvent with a metal foil (cation scavenger). Zinc aluminate crystals have been grown in a single step process using a chemical bath under optimised conditions in an average period of 15 days. Crystals were grown with hexagonal facets and XRD measurement confirmed the growth of a single crystal. Elemental (Zn, Al, O) and chemical compositional characterisation was done by EDAX. Thus the technique was found to be an advantageous low cost method for the growth of bulk single crystals of ternary oxide materials.

Keywords:

• COMPOUND SEMICONDUCTOR
• CRYSTAL GROWTH
• SINGLE CRYSTAL
• SPINEL OXIDE
• X-RAY DIFFRACTION