薄膜に現われる張力と膜の拡散クリープ

抄録

The nature of surface tension of liquid and crystal, the tension appearance in thin film, and their diffusional creep were discussed theoretically. The creep rate controlled by diffusion process for thin liquid film is shown as follows under the condition, σ_a being sufficiently large in (dε/dt)D₁(4/δ₂)(σ_aV/RT) comparison with the contribution of surface energy or tension, where ε is a strain observed on the film at time t, D₁ effective diffusion coefficient of liquid molecules, δ thickness of the film, σ_a applied external stress, and V molar volume of the liquid. Similarly the creep rate of the thin film of single crystal is shown for the condition where the (dε/dt)=D_s(4/δ₂)(σ_a²V/2ERT) value, (σ_a²V/2E), is sufficiently large in contrast with the molar surface energy of the film, where D_s is effective diffusion coefficient of solid atoms and E Young's modulus of the crystal.