Preparation of BaCrO ₄ particles in the presence of EDTA from aqueous solutions

BaCrO ₄ particles with well-defined morphologies have been synthesized in the presence of EDTA as a crystal growth modifier from aqueous solutions. The influence of pH on the morphology of BaCrO ₄ crystals with and without EDTA additive was investigated to better understand the formation mechanism. EDTA has a strong interaction with the crystal faces of BaCrO ₄ and influences the final morphology of BaCrO ₄ crystals. In the presence of EDTA, BaCrO ₄ particles at pH=6 always exhibit a spindle-like morphology due to the large inhibition effect of EDTA on the BaCrO ₄ crystallization. With decreasing pH, the particle morphology changes into a peanut-type at both pH=5 and pH=4 due to the relatively low inhibition and the following secondary heterogeneous nucleation and growth. The possible morphological evolution of BaCrO ₄ particles is also proposed.