X線によるセラミック膜の応力こう配の解析

概要

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The sin^2 ψ diagram taken from a specimen with steep stress gradients beneath the surface shows nonlinearity because the X-ray penetration depth changes depending on the tilt angle. Stress gradients can be determined from this nonlinearity. Since ceramic materials have a deep X-ray peretration depth, the thickness of a thin ceramic film should have a significant effect on the nonlinearity of the sin^2 ψ method. In this paper, we propose a method of X-ray measurement of the stress gradient which takes into account of the effect of the thickness of a film under the assumption of linear stress gradients. The film made of silicon nitride was prepared. A 58 μm thick film specimen was carefully polished with diamond slurry to obtain sharp profiles of the X-ray diffraction. To apply the linear stress gradients, the specimen was bent on a cylinder. The stress distribution estimated by the present method agreed well with the applied bending stress, From the present study, stress gradients should be analyzed in terms of the weighted average stress on the basis of the whole intensity of the diffracted X-rays from thin films. when the thickness is less than six times the effective X-ray penetration depth.
1997-06-25