Journal of Radio Electronics. eISSN 1684-1719. 2026. ¹8
Full text in Russian (pdf)
DOI: https://doi.org/10.30898/1684-1719.2026.8.2
STUDY OF THE ELECTRICAL CONDUCTIVITY
OF CALCIUM SULFATE DIHYDRATE (CaSO4·2H2O)
AND ITS POTENTIAL APPLICATIONS IN ELECTRONICS
V.S. Zakhvalinskii 1, T.B. Nikulicheva 1, A.V. Mashirov 2,
I.S. Nikulin 1, V.V. Vyazmin 1, D.N. Milostnoy 1
1 Belgorod National Research University, 308015, Russia, Belgorod, Pobedy str., 85
2 Kotelnikov IRE RAS, 125009, Russia, Moscow, Mokhovaya str., 11, b. 7
The paper was received June 9, 2026.
Abstract. This work is devoted to a comprehensive study of the structural and electrophysical properties of citrogypsum, a high-tonnage byproduct of biochemical citric acid production. Compacted test samples were fabricated via cold isostatic pressing. The chemical and phase compositions of the investigated anthropogenic raw material were determined using X-ray fluorescence and X-ray powder diffraction analyses. The surface morphology and textural characteristics were investigated by scanning electron microscopy and gas adsorption methods. The temperature dependence of the electrical conductivity of the samples was studied by broadband impedance spectroscopy in the frequency range of 200 Hz to 5 MHz under high vacuum conditions (10-3 mmHg) at temperatures of 250 K and 300 K using a Janis vacuum cryostat. It was established that at 300 K in the high-frequency region (330 kHz – 5 MHz), the complex impedance plot (Nyquist plot) is completely governed by the contribution of grain boundaries. The presence of two relaxation regions on the plot is attributed to the bimodal nature of the differential particle size distribution (~80 and ~500 μm), which is strictly confirmed by laser diffractometry data. Decreasing the temperature to 250 K leads to a transformation of the impedance profile in the low-frequency region (600 Hz – 1.1 kHz), manifested by the appearance of a linear diffusion contribution transitioning into a bulk transport arc; this behavior is successfully described by an equivalent circuit with a parallel combination of the grain bulk resistance (Rg) and capacitance parameter (Cg). The revealed features of electrical transport substantiate the potential of using modified citrogypsum matrices as functional dielectric media for the components of solid-state electronics.
Key words: calcium sulfate dihydrate, citrogypsum, industrial waste recycling, impedance spectroscopy, grain boundaries, Nyquist plot, equivalent circuit.
Financing: This work was supported by the Ministry of Science and Higher Education of the Russian Federation as part of the state task to create new laboratories, including under the leadership of young promising researchers as part of the national project «Science and Universities». The research topic is «Development and advancement of scientific and technological foundations for creating an integrated technology for processing gypsum-containing waste from various industrial enterprises and finding new ways to use the processed products» (grant number FZWG-2024-0001).
Corresponding author: Zakhvalinskii Vasilii Sergeevich, zakhvalinskii@bsuedu.ru
References
1. Zhang K., Schnoor J.L., Zeng E.Y. E-waste recycling: where does it go from here? // Environmental science & technology. – 2012. – Ò. 46. – ¹. 20. – Ñ. 10861-10867. https://doi.org/10.1021/es303166s
2. Nikulicheva T.B. et al. Using citric acid production waste as a new material for an air humidity sensor // International Journal of Environmental Science and Technology. – 2025. – Ò. 22. – ¹. 15. – Ñ. 15273-15288. https://doi.org/10.1007/s13762-025-06623-x
3. Nikulicheva T.B. et al. The possibility of practical application of citrogypsum in engineering // Technical Physics. – 2024. – Ò. 69. – ¹. 5. – Ñ. 1307-1315. https://doi.org/10.1134/S1063784224040297
4. Nikulin Ivan Sergeevich (RU), Nikulicheva Tatiana Borisovna (RU), Zakhvalinskii Vasilii Sergeevich (RU), Piliuk Evgenii Aleksandrovich (RU), Mishunin Maksim Vadimovich (RU), Patent for the invention of an air humidity sensor, RU 2 809 808 C1, Priority of the invention May 12, 2023.
5. Nikulicheva Tatiana Borisovna (RU), Zakhvalinskii Vasilii Sergeevich (RU), Nikulin Ivan Sergeevich (RU), Vitaly Vladimirovich Vyazmin, (RU), Resistive humidity control sensor, Utility Model Patent No. 234420, Priority of the utility model April 08, 2025.
6. Impedance spectroscopy: theory and application : textbook. manual / [Yu.V. Yemelyanova, M.V. Morozova, Z.A. Mikhailovskaya, E.S. Buyanova ; under the general editorship of E.S. Buyanova; Ministry of Education and Science of the Russian Federation. Federation, Ural. feder. un-T. Yekaterinburg : Izvo Ural. University, 2017. – 156 p.
7. Å. Barsoukov, J.R Macdonald. Impedance spectroscopy. Theory, experiment, and applications. 2nd ed.A. John Wiley & Sons, Inc., Publication, USA (2005). 583 p.
8. Boukamp B.A. Electrochemical impedance spectroscopy in solid state ionics: recent advances // Solid state ionics. – 2004. – Ò. 169. – ¹. 1-4. – Ñ. 65-73. https://doi.org/10.1016/j.ssi.2003.07.002
9. Battistel A. et al. Analysis and mitigation of the artefacts in electrochemical impedance spectroscopy due to three-electrode geometry // Electrochimica Acta. – 2014. – Ò. 135. – Ñ. 133-138. https://doi.org/10.1016/j.electacta.2014.05.011
10. Zhao H., Xiao X., Sun Q. Identifying Electric Shock in the Human Body via α Dispersion // IEEE Transactions on Power Delivery. – 2017. – Ò. 33. – ¹. 3. – Ñ. 1107-1114. https://doi.org/10.1109/TPWRD.2017.2766169
11. Simić M., Jeoti V., Stojanović G.M. Parameter extraction of the Cole-impedance model for in-situ monitoring of electrochemical sources // Journal of Energy Storage. – 2024. – Ò. 77. – Ñ. 109895. https://doi.org/10.1016/j.est.2023.109895
For citation:
Zakhvalinskii V.S., Nikulicheva T.B., Mashirov A.V., Nikulin I.S., Vyazmin V.V., Milostnoy D.N. Study of the electrical conductivity of calcium sulfate dihydrate (CaSO4·2H2O) and its potential applications in electronics // Journal of Radio Electronics. – 2026. – ¹. 8. https://doi.org/10.30898/1684-1719.2026.8.2 (In Russian)