%0 Journal Article
%A Röttger, A.
%A Weber, S.
%A Theisen, W.
%A Rajasekeran, B.
%A Vassen, R.
%T Mechanical properties of thermally sprayed Fe based coatings
%J Materials science and technology
%V 27
%@ 0267-0836
%C London [u.a.]
%I Maney Publishing
%M PreJuSER-19834
%P 973 - 982
%D 2011
%Z The authors gratefully acknowledge financial support by the Deutsche Forschungsgemeinschaft within the project 'Thermisches Spritzen von Fe-Basis MMC' (DFG project no. TH531/6-1; VA163/4-1).
%X The synthetic vanadinites (Pb(x)Ca(10-x))(VO4)6F2delta, 1 < x < 9, adopt a P6(3)/m apatite structure with 9.7590 (1) < or = a < or = 10.1179 (1) A and 7.0434 (3) < or = c < or = 7.4021 (1) A. The partitioning of calcium and lead over the AI(4f) and AII(6h) positions is nonstoichiometric with lead preferentially entering the larger AII site. High-resolution electron microscopy showed that samples annealed for 10 h at 1073 K are in disequilibrium with calcium- and lead-rich microdomains co-existing at unit-cell scales. For (Pb5Ca5)(VO4)6F2delta, sintering in excess of 2 weeks is required for the metals to order macroscopically. As annealing progresses, c/a, the partitioning coefficient kPb(AI/AII) and the AIO6 metaprism twist angle (phi) adjust cooperatively to enlarge the apatite channel, and thereby accommodate higher lead content. These results demonstrate that phi is a sensitive measure of disequilibrium and a useful device for monitoring changes in apatite topology as a function of composition.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:15017085
%U <Go to ISI:>//WOS:000291551000001
%R 10.1179/1743284710Y.0000000002
%U https://juser.fz-juelich.de/record/19834