Synthesis and characterization of ZrO2–MgO solid solutions by citrate gel process

The zirconia–magnesia (ZrO2–x mol% MgO; x = 3–90) solid solutions were prepared by the citrate gel method. The phase identification and crystallite size of the samples were obtained using X-ray diffraction. Raman spectroscopy was performed to distinguish between cubic and tetragonal phases. The metastable tetragonal t′-form was determined in MgO-doped ZrO2 calcined at 800 °C. Samples containing up to 50 mol% MgO were revealed to be monoclinic ZrO2 solid solution and MgO when calcined at 1000 °C. Moreover, ZrO2–x mol% MgO (x = 60–90) solid solutions have metastable tetragonal t′ with MgO phase at 800 and 1000 °C, whereas no cubic phase was determined at any compositions of zirconia-based solid solutions. The prepared powders were characterized by transmission electron microscopy (TEM) to obtain the size and the morphology of the particles.