激光刻蚀工艺对Al_2O_3-ZrO_2固溶度和结晶度的影响

Influences of Laser Ablation Processes on Solubility and Crystallizability of Al_2O_3-ZrO_2 Nanopowders

利用X射线衍射, X射线吸收精细结构谱和高分辨电镜研究了激光刻蚀工艺对 Al2O3-ZrO2固溶度和结晶度的影响．结果表明,Al2O3在ZrO2中的固溶度越大,ZrO2晶体结构无序度越大．样品室的空气压力越大,粉体中无定形相的含量越大．无定形ZrO2中存在短程有序-长程无序结构Zr-O—Zr(Al)．同Al2O3-ZrO2固溶体相比,无定形ZrO2具有更短的 Zr-O和Zr-Zr(Al)原子间距离和更大的无序度．

The influences of laser ablation processes on the solubility and the crystallizability of laser evaporated Al2O3-ZrO2 nanopowders were studied by X-ray diffractometer （XRD）, X-ray absorption fine structure （XAFS） spectroscope and high resolution electron microscope （HREM）. Results indicate that ZrO2 crystalline lattice with an increasing solid solubility exhibits larger disorder. Increasing air pressure in the sample chamber favors the formation of amorphous ZrO2. Amorphous ZrO2 consists of Zr-O-Zr （Al） clusters with short-range order but long-range disorder. The Zr-O and Zr-Zr （Al） interatomic distances in amorphous ZrO2 are shorter and the disorder of amorphous ZrO2 is larger than that of crystalline Al2O3-ZrO2 solid solutions.