Statistical parameters for rough surfaces of thin films of CaF(2) and Ag/CaF(2).

Statistical parameters, rms roughness delta and autocovariance length sigma, are determined both for rough surfaces of CaF(2) deposits and for surfaces of silver films deposited on these CaF(2) underlayers. The dependence of delta and sigma on the CaF(2) film thickness d is investigated. It is shown that the silver films do not replicate well the CaF(2) underlayers. A review of the relationships between delta, sigma and d when seeking control of the roughness of a silver film by controlling d is proposed. It is also shown that CaF(2) is a good underlayer compared with LiF.

Quantitative characterization of a biological membrane by means of its spatial autocovariance.

Profiles for the exoplasmic face (EF) of the freeze-fractured plasma membrane from the root storage tissue of red beets are reconstructed by microdensitometry of micrographs of surface-shadowed-platinum carbon replicas. Autocovariance functions (ACFs) are computed from those profiles. The initial portions of the ACFs have a Gaussian form whose parameters (root mean square surface roughness and autocovariance length) are estimated. The parameter estimates are used to show that the pits on the EF faces are in good complementarity with the intramembrane particles seen on the complementary protoplasmic fracture faces.

Height and slope distributions for surfaces of rough metallic deposits.

This paper deals with the accurate determination of height and slope distributions for surfaces of rough metallic deposits (magnesium, copper, silver, and gold). These distributions are computed using a microdensitometer analysis of electron micrographs of surface replicas. It is shown that most of the surfaces examined have reasonable Gaussian height and slope distributions. Apart from magnesium surfaces, the rms roughnesses determined from these distributions agree (within the accuracy range of their measurements) with rms roughnesses deduced from the autocovariance functions computed previously. Within the framework of scalar scattering theory, some emphasis is laid on the value of slopes to draw certain conclusions about the validity of the assumptions under which the scalar scattering theory is derived.