Electrical conduction and diffusion studies in NH 4H 2PO 4 and KH 2PO 4 single crystals

Electrical conduction (dc) studies are made with pure and cobalt(II)-doped single crystals of NH ₄H ₂PO ₄ and KH ₂PO ₄. The effect of the dopant concentration on the enthalpy for the migration of protons and the enthalpy for the rotation of the H ₂PO ₄ group have been studied. It is suggested that proton migration occurs through a synchronous phosphate rotation mechanism. Tritium diffusion studies in KDP and ³²PO ₄ diffusion in ADP crystals have been made. The mechanisms for the conduction and diffusion processes are found to be different in nature. The distribution coefficients of Co(II) dopant in ADP (2.92 × 10 ^-3) and KDP (1.14 × 10 ^-3) are calculated. The following enthalpy values are obtained.