Eh © j Mierost 
} E 10,3 Jaroslam 
3 ’ Vechnica 
j 
Fe 
; Introducth 
20° Ben 
© ry phases mi 
sedimentation of spheres RL 
Low Dovey 0 Averaging over 700 points nam 
Fig. 11: Calculation of gradient of sedimented glass spheres or 
[PRG 
Conclusion 
The purpose of this work was to describe the gradient of pores and particles sizes in ceramic 
materials, especially for filtration membranes with pores sizes down to the range of 10 nm. At first 
methods for preparing cross sections of these layer materials were developed. The analysis of the m 
microstructures was performed with help of a high resolution scanning microscope. We can detect oe 
pore sizes in the 60 nm layers by means of cross section specimens. A way also to resolve pores Tr 
< 60 nm is shown by the first results with a slope cutting method layered membranes. The high Lo 
resolution at optimum contrast is the prerequisite for quantitative image analysis with a sufficient Co 
statistic. On this basis the gradient in porous graded membrane layers is also possible to be 5 
calculated. The methods to describe the gradient were tested by sedimentation of glass spheres, i. 
objects, which exactly fulfil one of the conditions of this method, the spherical shape. In the next 1 
steps materials with different particle shapes shall be investigated, to show the evidence that this 
method shows a universal character. 
Acknowledgement 
We acknowledge the help in preparation of ion beam cut slopes by Dr. Griinewald from the 
company BAL-TEK and the German Research Society for the financial support at the enforcement : 
of these experiments. : 
Reference 
/1/ Moritz, T; Tomandl, G.; Werner, G.; Mangler, M.: in press war 
/2/ Puhlfürß, P. Voigt, A.; Weber, R.; Morbe, M.: J. Membrane Science 174 (2000) 123-133 ano 
/3/ Tomandl, G.; Mangler, M.; Pippel, E., Woltersdorf, J.: M. Chem. and Phys. 63 (2000) 139-144 a 
/4/ Tomandl, G.: Prakt. Metallographie 16 (1979) 413-419 
/5/ Hahn, U. : Stoyan, D.: Adv. Appl. Prob. 30 (1998) 904-920 
/6/ Grünewald. W.; Hietschold M.: Proc. of 12” Europ. Congr. on Electron Microscopy, July 2000 
170