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A series of layered CuCr1-xMgxO2 (0 ≤ x ≤ 0.08) polycrystalline ceramics were prepared. The effects of substituting Mg2+cations for Cr3+ cations on the grain composition, grain size, grain quantity, and electrical conductivity were investigated. When x = 0–0.04, the distinct layered structure grain grew rapidly with the increase of magnesium in the composition, andthe average grain size increased from 2.5 μm (x = 0) to 15 μm (x = 0.04) due to the decrease of activation energy. Furthermore,the bulk density and lattice constant also reached the maximum and minimum values of 4.367 g/cm3 and 17.083 respectivelyat x = 0.04. When x = 0.05–0.08, the average grain size slightly decreased due to the grown-up second-phase MgCr2O4hindering of grain growth. The results showed that the average size of the second-phase MgCr2O4 had reached 1.3 μm whenx = 0.04. In general, the larger the grain size of polycrystalline ceramics, the more defects in the grain boundaries, and thebetter its electrical conductivity. Therefore, the solid-phase reaction, which can obtain larger grain size and more grainboundary defects, was chosen here to prepare CuCr1-xMgxO2 polycrystalline ceramics, so as to obtain a highly conductiveCuCr1-xMgxO2 ceramic material. The minimum resistivity of the obtained CuCr0.6Mg0.4O2 polycrystalline ceramic is only 0.091Ω·cm, which is of great significance for the development of transparent conductive oxides.
