Development of the System for Measuring Elastic Modulus of Ceramics Thin Films under the Various Atmospheres

为了测量陶瓷薄膜的弹性性能，研制了悬臂梁振簧法测量系统。杨氏模量和泊松比都可以确定。用该系统测量了溅射铝膜和非晶SiO_2膜的弹性模量。所得值与它们的块状材料的弹性模量吻合较好。结果表明，所研制的测量系统是测定陶瓷薄膜弹性常数的有力手段。此外，还测量了SiO_2-Al_2O_3和AlPO_4-Al_2O_3体系中rf溅射非晶膜的弹性模量。根据体积模量与平均原子体积的关系，评价了铝离子在非晶膜中的配位状态。所得结果与我们用其它物理性质数据测定铝离子配位态的结果吻合较好。为了测量薄膜在高温下的弹性模量，研制了一种采用振动共振法的测量系统。利用该测量系统测量了沉积铝膜的杨氏模量及其温度系数。这些数值与大块铝的杨氏模量及其温度系数吻合较好。结果表明，该测量系统是测定薄膜高温杨氏模量的有效手段。此外，还测量了用射频溅射法制备的非晶AlPO_4薄膜的杨氏模量温度系数。该系数为正值。杨氏模量的正温度系数“弹性异常”是开放网络结构的非晶态材料（如SiO_2和GeO_2玻璃）的特征。结果表明，无定形ALPO_4薄膜具有由AlO_4和PO_4四面体组成的三维网状结构。

For the purpose of measuring elastic properties of ceramics thin films, the measuring system using the cantilever beam vibrating reed method was developed. Both Young's modulus and Poisson's ratio can be determined. The elastic moduli of the sputtered aluminum and amorphous SiO_2, films were measured by this system. The obtained values were good agreement with the elastic moduli of their bulky materials. The results show that the developed measuring system is a powerful means to determine the elastic constants of ceramic thin films. In addition, the elastic moduli of rf-sputtered amorphous films in the systems SiO_2-Al_2O_3 and AlPO_4-Al_2O_3 were measured. The coordination state of aluminum ions in the amorphous films were evaluated from the relationship between the bulk modulus and the mean atomic volume. The obtained results are good agreement with our results of the coordination state of aluminum ions determined by the data of the other physical properties.In order to measure the elastic modulus of thin films at high temperature, the new measuring system, which uses the vibrational resonance method, was developed. By this measuring system, Young's modulus and its temperature coefficient of a deposited aluminum film were measured. These values were good agreement with Young's modulus and its temperature coefficient of bulky aluminum metal. This result shows that the measuring system is an efficient means to determine Young's modulus of thin film at high temperature. Moreover, the temperature coefficient of Young's modulus of an amorphous AlPO_4 film, prepared by rf-sputtering method, was measured. The coefficient was positive value. The positive temperature coefficient of Young's modulus, "elastic anomaly", is characteristic of the amorphous materials with an open network structure, such as SiO_2 and GeO_2 glasses. This result shows that an amorphous ALPO_4 film has a three dimensional network structure made of AlO_4 and PO_4 tetrahedra.