以草酸为络合剂，采用溶胶–凝胶法制备一系列氧化镁稳定氧化锆粉末 Zr1−xMgxO2−x(0.04≤x≤0.10)，利用 X 射线衍射(XRD)、场发射扫描电镜(FESEM)等分析技术对粉末进行表征。结果表明，掺杂氧化镁后，低温350~450℃煅烧产物晶型为四方相(t-ZrO2)，随煅烧温度升高，t-ZrO2逐渐向 m-ZrO2转变。在550℃下煅烧时，少部分四方相转变为单斜相(m-ZrO2)，转变比例随掺杂量增加而降低。Mg2+取代 Zr4+产生氧缺陷是 ZrO2晶体结构稳定的主要因素。随煅烧温度从350℃升高到650℃，Zr0.92Mg0.08O1.92粉末中 t-ZrO2晶粒尺寸从42 nm 长大到100 nm；随 Mg 掺杂量从0.04增加到0.10，t-ZrO2晶粒尺寸从110 nm 减小到97.8 nm，而纳米尺寸晶粒有利于 t-ZrO2稳定。%Nano-powder magnesia stabilized zirconia Zr1−xMgxO2−x powders were prepared by sol-gel process using oxalic acid as precipitant. The crystal phase composition and structure of oxide powders were determined by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM), respectively. The results of XRD show that tetragonal phase ZrO2 and little monoclinic phase ZrO2 form at 550 ℃, while the tetragonal Zr1−xMgxO2−x forms at 350 ℃. When x is below 0.08 and with temperature increasing, part of t-ZrO2 transforms to m-ZrO2 , and the ratio of transformtion decreases with increasing x value, when x is above 0.10, t-ZrO2 transformation ratio increases with increasing temperature. The generation of oxygen defect after Mg2+ replacing Zr4+ is the main factor to influence the stabilization of the ZrO2 crystal structure. The crystillize size of t-ZrO2 increases from 42 nm to 100 nm when temperature increases from 350 ℃ to 650 ℃, and t-ZrO2 crystillize size decreases from 110 nm to 97.8 nm with MgO-doped amount increases from 0.04 to 0.10. Nano grain size is favorable for the stability of t-ZrO2.
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