|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1992 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1991 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Among various properties of solid materials, elastic properties such as Young's modulus, bulk modulus, shear modulus and Poisson's ratio are of considerable interest from both scientific and technical aspects. It is known that the glasses containing the constituents with high bond strength and/or having high coordinated state of network forming cations could achieve high elastic moduli. However, since it is not easy to make the glasses with high coordinated state of cations by ordinary melting-quenching procedure, other glass making processes such as sputtering, CVD and sol-gel methods have to be explored. In this project, radio-frequency sputtering method was applied to make amorphous thin films in the systems Al_203-AlN and Al_2O_3-TiO_2. The elastic moduli commonly increase as nitrogen is introduced into a glass. However, in the Al_2O_3-AlN system, the elastic moduli decreased as AlN was added to amorphous Al_2O_3. This result can be successful to be explained by decrease of the higher coordinated aluminum ions. On the other hand, the high coordinated state of cations could be achieved in rf-sputtered amorphous films in the system Al_2O_3-TiO_2, and their elastic moduli were measured. The amorphous film of 16Al_2O_3.84TiO_2 showed the maximum value of Young's modulus, 175GPa, in this system, which is higher than any other glass ever known.