Experimental Study of Polarization Clusters in 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 Relaxor Ferroelectrics by means of Synchrotron Radiation X-ray Diffraction

摘要

X-ray diffraction has been conducted to study the microscopic-scale structures for 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 relaxor ferroelectrics in a high external DC field during phase transition. Clear quasi-periodic structures were observed along 111 and 1-11 directions near Tc induced by the high external DC field. The formation of these periodic structures are interpreted as a type of Coulomb interaction among adjacent polar clusters. The cluster size was estimated to be 17nm. It was also found that the dominating interaction direction among clusters (periodic direction) were changeable among 111 and 1-11 as temperature changed.