Effects of ammonium citrate additive on crystal morphology of aluminum phosphate ammonium taranakite

In this communication, we demonstrated the growth of aluminum phosphate ammonium taranakite (NH4-AlPO4) crystals from regular hexagonal form into the disk-like form could be controlled by ammonium citrate (AMC) as the effective crystal growth modifier at 90 °C. Prepared crystals were characterized by field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of AMC's concentration on the crystal form and morphology of NH4-AlPO4 were studied. The results showed that the AMC's concentration is an important parameter to control the size and morphology of NH4-AlPO4 crystal. The formation mechanism of the special morphology of NH4-AlPO4 crystals was also analyzed.