ABSTRACT OF HONORS PROJECT
                
                              Project report

                      

                            Andrews University
                    
                       College of Arts and Sciences





        Title:   X-RAY RADIAL DISTRIBUTION STUDIES OF AMORPHOUS
                 GERMANIUM-ANTIMONY-CHALCOGEN ALLOYS
         
        Name of researcher:  Keith G. Calkins

        Name of faculty advisor:  S. Clark Rowland, Ph.D.

        Date completed:  September 1988



                A 1985 x-ray radial distribution function (rdf)
        
        study of amorphous germanium-antimony-chalcogen alloys

        needed careful reanalysis due to inconsistent results.

        This study was the latest in a series of rdf studies

        involving a metal (Pd, Sn, Ag, Bi) in a germanium-chalcogen

        glass.  As part of the reanalysis, new data on old samples

        as well as data on a new sample had to be analyzed.  There

        was also a need for written procedures for the computer

        analysis and other aspects of this research.

                Density estimates and measurements were made and
        
        compared with prior estimates.  A density measurement

        procedure was written.  Computer programs were carefully

        checked for accuracy, corrections made, documentation and

        enhancements added, and a computer analysis procedure

        written.

                It was concluded that the coordination number of
        
        antimony is between 3.0 and 4.0.  Two sulfur samples (20.00

        and 25.00 at. % antimony) yielded coordination numbers

        significantly higher than the others.  In addition, these

        two samples are well represented by both models considered,

        possibly yielding even higher results.  Excluding these two

        samples, all coordination numbers were in the range 3.0-

        3.6.  This range is consistent with a coordination number

        of three as expected from the 8-N rule.  Chalcogen

        coordination numbers of 1.7-2.1 were obtained, also

        consistent with the expected value of two.

                As a result of this project, not only were new,
        
        publishable results obtained, but also the accuracy and

        repeatability of future radial distribution studies should

        be increased.  Improved recording of procedures done and

        organization of laboratory notes should also occur with

        less effort expended.