A homologous series Pb2n+1Nb2n−1O7n−1 studied by electron microscopy Ch. Leroux, T. Badeche, G. Nihoul, O. Richard and G. van Tendeloo Eur. Phys. J. AP, 7 1 (1999) 33-40 Published online: 15 July 1999 DOI: 10.1051/epjap:1999196