形变多晶氧化铝纤维的荧光R谱线

使用自制拉伸装置和显微拉曼系统测定了形变下多晶氧化铝纤维的荧光R1和R2谱线,发现两条谱线均随纤维拉伸应变的增大而变宽,并获得了纤维应变与谱线宽化值之间的定量关系。从纤维的结晶晶格结构和形态学微结构定性地解释了谱线的宽化行为。也测定了谱线频率与多晶氧化铝纤维温度间的定量关系,频率温度系数值近似等同于单晶氧化铝的值。最后,研究了激发光偏振方向相对于纤维轴向的不同夹角对谱线频率的影响,并由此得出,氧化铝晶粒有相对纤维轴向取向的倾向。

The Behavior of Fluorescence R Line of Deformed Polycrystalline Alumina Fibers

The behavior of R1 and R2 line of both polycrystalline alumina and alumina-zirconia fibers has been investigated using a combination of tensile rig and micro-Raman system.It was found that there were a considerable line broadening for both materials under the action of tensile strain(or stress) and the broadening was approximately linearly dependent upon strain for both types of alumina fiber.The behavior was interpreted from crystal lattice and morphological microstructure of fibers.The dependence of line shift upon fiber temperature was also measured.The result indicated that there was a linear shift in wavenumber with temperature at the measured range of temperature,which was consisted with that for single crystal alumina.Finally the line shifts for different polarized direction of laser beam with respect to fiber axis for the free-standing fiber were measured.It is found that line shift was closely relative to polarized direction,which might originate from preferential orientation of grains along fiber axis.