@article{escidoc:0428, title = {{Magnetization study of nanograined pure and Mn-doped ZnO films: formation of a ferromagnetic grain-boundary foam}}, author = {Straumal, B. B. and Mazilkin, A. A. and Protasova, S. G. and Myatiev, A. A. and Straumal, P. B. and Sch\"utz, G. and van Aken, P. A. and Goering, E. and Baretzky, B.}, journal = {{Physical Review B}}, volume = {79}, year = {2009}, doi = {10.1103/PhysRevB.79.205206} }