The determination of thin film thickness by four X-ray reflectivity methods (namely, the peak separation, the Fourier transform, the modified Bragg equation, and the curve-fitting methods) has been studied. An analysis of SrS and BaF2 thin films showed thickness values determined by the methods agreed to within 4%. The curve-fitting method had the highest accuracy but was time-consuming. The peak separation, the Fourier transform, and the modified Bragg equation methods are considerably faster and, on average, gave 2.8%, 0.9%, and 0.2% larger thicknesses than those of the curve-fitting method.

Stimulable phosphor thin films are being investigated for use as optical data storage media. We have successfully applied atomic force microscopy (AFM) to the measurement of the surface texture of these films. Determination of the surface texture of the films is important for evaluating the effect of surface quality on optical scatter. In other thin film material systems it has been found that the surface “bumps” revealed by AFM correspond to grains in the film. This is not the case for the stimulable phosphor films used in our study. We have determined the grain size of our phosphor films by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The grain size from TEM and XRD does not correlate with the size of the AFM surface “bumps.” For example, in two of the five films studied, the XRD derived grain size varies by a factor of two but the size of the surface “bumps” remains the same. We conclude that the texture of the film surface is not directly determined by the grain size of the phosphor material.

Strontium sulfide doped with europium and samarium is an infrared stimulable phosphor that is being investigated as the active thin film layer of a photonic data storage disk. Lithium and fluorine can be added to the SrS:͑Eu,Sm͒ to fully activate the photonic properties of the material, and care must be taken to ensure sufficient crystallite size, minimize structural defects within crystal grains, and maintain a uniform chemistry throughout the film thickness. In this article we present the initial stages of a study of the relationship of these properties to film performance. A number of techniques are employed including x-ray diffraction, electron probe x-ray microanalysis, transmission electron microscopy, and secondary ion mass spectrometry. Initial findings provide information on the effect of structural defects on film performance, and the importance of the mismatch in thermal coefficient of expansion between film and substrate.