Cu_0.25- Mn_0.25 VOPO₄ .4H₂O (Cu-MnVPO) and Cu_0.30 -Zn_0.19 H_0.01 VOPO₄ 1.8 H₂O (Cu-ZnVPO) have been prepared from reactions of mixtures Cu²⁺-Mn²⁺ and Cu²⁺-Zn²⁺ metal ions with VOHPO₄.0.5H₂O. They were characterized by chemical, thermal analysis, X-ray powder diffraction and by FT-IR spectroscopy. Their conductivity determinations were made by ac-method at temperature ranges (25 -85°C) on compact discs using silver paste as electrodes. The variation of the ac conductivity as a function of frequency in the range 10Hz - ¹⁰KH was also studied . For the compound CuZnVPO, it is observed that ac conductivity increases with increasing temperature from room temperature up to 57°C , then another phase starts to form . In the range of 57-85°C , the ac conductivity reaches its maximum value, 9.4X10^-4 mho m^-1, and then remains constant. In case of CuMnVPO, the conductivity reaches its minimum value 5.5X10^-4 mho m^-1. The ac conductivity decreases with increasing temperature up to the transition point 72°C, where a new phase starts to forms and the conductivity remains constant. The activation energies for CuMnVPO and CuZnVPO, were calculated in the range 25°C to transition point and found to be 0.19, 0.12 (Ev)

Keyword: Electrical properties , intercalated Cu²⁺-Zn²⁺ and Cu²⁺⁺Mn²⁺ , α-vanadyl hydrogen phosphate hemihydrate.

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