WFD-2　Ferroic domains in conventional and relaxor ferroelectrics ‐ observed by SPM and evidenced by dielectric wall response Wolfgang Kleemann Angewandte Physik, Universitat Duisburg-Essen, D-47048 Duisburg, Germany 　　　　　Direct observation of ferroelectric domains by using scanning probe microscopy 　　　　　(SPM, viz. atomic force and piezoelectric force scanning microscopy, AFM and PFM, 　　　　　respectively) is considered for two limiting cases. On one hand, pure crystals showing 　　　　　conventional ferroelectricity like PbTiO3 reveal regular ferroelectric-ferroelastic 　　　　　domains, while strongly charge disordered relaxor ferroelectrics like Sr0.61Ba0.39Nb2O6 　　　　　(SBN) develop irregularly structured random-field controlled domains. The physical 　　　　　principles governing both phenotypes are explained within the frame of simple models. 　　　　　　　　Indirect evidence of domain walls is deduced from dielectric spectroscopy. 　　　　　Impurities in pure ferroelectric crystals like periodically poled KTiOPO4 (KTP) on 　　　　　one hand and charge disorder in uniaxial relaxor ferroelectrics like SBN on the other 　　　　　hand give rise to friction-controlled creep and slide response at ultralow frequencies, 　　　　　and to local segmental relaxation in the rf range. An appropriate model describing the 　　　　　domain kinetics and the corresponding polydispersive dielectric response will be 　　　　　discussed.