Stability of KH2PO4 and K(H,D)2PO4 solutions at fast crystal growth rates

Abstract The stability of KH 2 PO 4 (KDP) and K(H,D) 2 PO 4 (DKDP) solutions was investigated under the conditions required for rapid growth of large crystals. A metastable zone of up to 40°C in width and induction periods of more than 3 months were obtained in stirred solutions. Values for the surface free energy, α, of 11.9 and 12.9 mJ/m 2 were calculated for 40 and 30°C, respectively. High quality single crystals of 5–16 cm in size were grown at growth rates of 10–40 mm/day without spontaneous nucleation.