Stanislav Novák

Morphological study of discontinuous and semicontinuous metal films

The morphology of thin metal films is investigated by computer experiment. In the initial stages of film growth, the theory of mathematical morphology provides convenient methods for the characterisation of spatial distribution of islands in these films by the radial distribution function and/or by the distribution of nearest-neighbours. In the paper, the range of validity of standard morphological methods is tested, and methods for the analysis of thicker metal films are suggested. It was found that the covariance function is useful even in cases when other simple morphological methods cannot be used.

Multilevel morphological analysis of continuous films and surfaces

New methods of image analysis are discussed and tested in the contribution by mean of computer experiment. All methods are designed for the study of multilevel images, where the information is stored in the grey scale of the image. The first approach is based on standard bilevel morphological methods and an attempt is made to extend their range of validity. In the second approach, the multilevel image is conversed into a set of bilevel images and these images are processed simultaneously. As the third approach giving the best results, a genuine multilevel image analysis based on gradient methods is suggested. All these techniques are implemented as computer programs and can be applied to the data derived from experiments with continuous metal films and surfaces.

Computer study of object distribution in composite films

A computer experiment is used to study the possible partial reconstruction of three-dimensional (3D) structures from their two-dimensional (2D) projections or sections. The model prepared in this article attempts to solve the problem of estimation of structure randomness. A new Cube Counts Method (CCM) for the testing of randomness of 3D structures is presented. Standard morphological characteristics of 2D sections are tested in order to examine the capabilities to estimate the randomness of the 3D structure.

Study of morphology of composite films

The need for the reconstruction of three-dimensional structures from two-dimensional sections or projections is well known. We use the computer experiment to study the problem. Four models all with spherical objects were prepared to study the possibility of at least partial reconstruction of three-dimensional structures from their two-dimensional sections. The criterion on how to judge whether the reconstructed structure consists of constant size objects is given. There are discussed errors caused by the influence of limited numbers of objects or of digitisation. In the paper the use of the integral transform method to unfold the structures is illustrated. The results of the structure reconstruction are presented. They give us the conviction that the method is widely usable not only for spherical objects.

Morphological analysis of continuous metal films

During the study of images in thin-film physics the methods convenient for the quantitative description of film photographs must be applied and the connection between the morphological characteristics obtained and physical properties of the films established. In the case of semicontinuous and continuous films, whose micrographs can be described in terms of image processing as grey scale images as opposed to bilevel pictures of discontinuous metal films, the methods of characterisation of film micrographs are still to be invented and proper physical interpretation found. In this paper two methods of image analysis of multilevel pictures in physics are suggested and their applicability tested by computer experiment.

Computer simulation of semicontinuous and continuous metal film morphology

Abstract The methods convenient for the morphological analysis of very thin metal films are analysed by the computer simulation technique. An attempt is made to extend the range of validity of methods developed for the study of discontinuous films using these methods to describe both structures with irregular objects and thicker semicontinuous and continuous structures. It was found that the covariance function, one of the basic methods for the characterisation of spatial distribution of objects in discontinuous metal films, is a convenient approach even in the case when other simple morphological methods cannot be used at all. In order to derive the physical meaning of the information obtained from the covariance curves a computer experiment based on four models in three modifications for discontinuous, semicontinuous and continuous structures was performed.

Morphological analysis of discontinuous and semicontinuous metal films

In the paper, the morphology of discontinuous metal films with irregular islands and of semicontinuous metal films is studied by the combination of computer experiment and analysis of film micrographs. In order to determine the physical interpretation of derived morphological characteristics, four models in two modifications for both discontinuous and semicontinuous metal films were prepared. These models were analysed by the standard morphological algorithms for description of spatial distribution of objects and the physical meaning of these characteristics for irregular objects was discussed. It was found that although the sensitivity of methods used decreases with increasing film thickness, the covariance method is the most promising of them.

Study of electron transport in composite films below the percolation threshold

Composite and nanocomposite films consisting of metal objects embedded in a dielectric matrix are studied by computer experiment. The electron transport through the composites is calculated in the case when the basic conductivity mechanism is the tunnel effect. It was found that the conductivity of composite film is located into tunneling clusters strongly influenced by objects arrangement in composite film.

Morphology versus conductivity of nanocomposite films

A computer experiment for the study of transport and morphological properties of composite/nanocomposite films is presented. Features based on the theory of mathematical morphology describe the film morphology. The electrical transport in composite films is simulated stochastically near the metal-dielectric transition, where the basic mechanism of charge transport is the tunnel effect. The results of morphological and transport analysis of modelled composite structures are compared and discussed.

Morphological Characteristics of Composite Films

For the testing of methods for morphological analysis of composite films, a computer experiment was suggested. Two models were prepared to study the possibility of at least partial reconstruction of 3D structures from their 2D projections or sections. The importance of some morphological characteristics for the reconstruction of size and/or spatial distribution of objects is shown in the paper. It illustrates the usage and significance of the integral transform method for the unfolding of the structures, too.