Semiconductor Physics, Quantum Electronics & Optoelectronics, 26 (3), P. 255-259 (2023).
DOI: https://doi.org/10.15407/spqeo26.03.255
Role of ZnMn2O4 phase in formation of varistor characteristics in ZnO:Mn ceramics
1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41, prosp. Nauky, 03680 Kyiv, Ukraine Abstract.
The samples ZnO:Mn were prepared using the conventional solid-state technique. To dope them with manganese, we used water solutions of MnSO4 and MnCl2. The properties inherent to both types of the obtained ceramics have been compared. It was found that the former demonstrated nonlinear current-voltage characteristics, whereas those of the latter were, in fact, linear. The analysis of EPR, diffuse reflectance and Raman spectra obtained for prepared ceramics allowed concluding that, in the samples doped with MnSO4, formation of Mn-related phase, namely, ZnMn2O4 spinel occurred at ZnO grain boundaries under sintering. It has been ascertained that a thin layer of this substance separates adjacent ZnO grains, which provides appearance of the back-to-back Schottky barriers at grain boundaries and “varistor behavior” of current-voltage characteristics.
Keywords:ZnO:Mn ceramics, EPR, diffuse reflectance, Raman spectra.
I.V. Markevich1,
T.R. Stara1,
I.P. Vorona1,
O.F. Isaieva1,
Ye.G. Gule1,
O.V. Melnichuk2,
L.Yu. Khomenkova1,*
2Mykola Gogol Nizhyn State University, 2, Grafska str., 16000 Nizhyn, Ukraine
*Corresponding author e-mail: khomen@ukr.net
This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.