Growth of KH₂PO₄ Single Crystal with an Artificial Isotope Gradient

Abstract

KH₂PO₄ (KDP) single crystals internally including an artificial isotope gradient are grown by a controlled solution-recrystallization method. The deuteron exchange rate of KDP single crystal is spatially tailored through crystal growth in a KD₂PO₄ (DKDP) saturated solution, where the deuteron concentration decreases with time. The position dependence of the deuteron concentration was precisely determined with confocal micro-Raman scanning giving a change in the Raman spectrum as a proof. The result indicates that the deuteron concentration continuously varies from 77 % to 7 % within 100 microns.

Keywords:

• Ferroelectrics
• hydrogen-bond
• isotope effect
• graded material