Sreeraj, P. [P:(DE-HGF)0] ; Wiemhöfer, H.-D. [P:(DE-HGF)0] ; Hoffmann, R.-D. [P:(DE-HGF)0] ; Skowronek, R. [P:(DE-Juel1)VDB59998] ; Kirfel, A. [P:(DE-HGF)0] ; Pöttgen, R. [P:(DE-HGF)0]