Comparative Analysis of the Electrical Properties of Nanocrystalline NiMoO4 Hydrate and α-NiMoO4 Obtained by Hydrothermal Method

Authors O.M. Popovych, I.M. Budzulyak , O.V. Popovych, V.O. Kotsyubynsky , L.S. Yablon

Vasyl Stefanyk Precarpathian National University, 57, Shevchenko St., 76018 Ivano-Frankivsk, Ukraine

Issue Volume 13, Year 2021, Number 6
Dates Received 23 September 2021; revised manuscript received 02 December 2021; published online 20 December 2021
Citation O.M. Popovych, I.M. Budzulyak, O.V. Popovych, et al., J. Nano- Electron. Phys. 13 No 6, 06007 (2021)
PACS Number(s) 81.07.Bc, 84.37.q
Keywords Nickel molybdate, Hydrothermal synthesis (3) , Impedance analysis, Electrical conductivity (10) .

We have investigated the impedance behavior and electrical conductivity of nanocrystalline hydrate and α-phase of nickel molybdates obtained by hydrothermal method. Frequency behavior of the real impedance part of obtained nickel molybdates points at space charge polarization under the impact of an applied electric field. The imaginary impedance component of α-NiMoO4 substance proves the absence of relaxation in it, meaning that the transport of charge carriers between grains is possible in the whole frequency range. At the same time, we observe a temperature-dependent relaxation process for NiMoO4 hydrate in the temperature range 175-200 C caused by defects, namely vacancies. It has been shown that the conductivity of NiMoO4 hydrate at a direct current is equal to 4·10 – 5 S/m, whereas for NiMoO4 α-phase it is 1.5·10 – 4 S/m at room temperature due to the conditions for obtaining materials. The temperature dependencies of the frequency exponent s that we obtained make it possible to assert that the ac conductivity of NiMoO4 hydrate can be explained on the basis of the correlated barrier hopping model, whereas of α-NiMoO4 – by small polaron tunneling model.

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