%0 Journal Article %T Structure and Physical Properties of PZT-PMnN-PSN Ceramics Near the Morphological Phase Boundary %A Nguyen Dinh Tung Luan %A Le Dai Vuong %A Truong Van Chuong %A Nguyen Truong Tho %J Advances in Materials Science and Engineering %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/821404 %X The 0.9Pb(ZrxTi1£¿x)O3-0.07Pb(Mn1/3Nb2/3)O3-0.03Pb(Sb1/2Nb1/2)O3 (PZT-PMnN-PSN) ceramics were prepared by columbite method. The phase structure of the ceramic samples was analyzed. Results show that the pure perovskite phase is in all ceramics specimens. The effect of the Zr/Ti ratio on the region of morphotropic phase boundary for PZT-PMnN-PSN ceramics was studied. Experimental results show that the phase structure of ceramics changes from tetragonal to rhombohedral with the increase of the content of Zr/Ti ratio in the system. The composition of PZT-PMnN-PSN ceramics near the morphotropic phase boundary obtained is the ratio of Zr/Ti:£¿49/51. At this ratio, the ceramic has the optimal electromechanical properties: the , the , the £¿pC/N, the , high remanent polarization ( £¿¦ÌC¡¤cm£¿2), and low coercive field £¿kV¡¤cm£¿1. 1. Introduction Lead zirconate titanate (PZT) is one of the most commonly used ferroelectric ceramic materials. The material has been studied intensively since discovery of the miscibility of lead titanate and lead zirconate in the 1950s [1¨C5]. Due to their excellent dielectric, pyroelectric, piezoelectric, and electrooptic properties, they have a variety of applications in high energy capacitors, nonvolatile memories (FRAM), ultrasonic sensors, infrared detectors, electrooptic devices, and step-down multilayer piezoelectric transformers for AC-DC converter applications [5, 6]. Until now, many ternary and quaternary systems, such as Pb(Ni1/3Nb2/3)O3-PZT, Pb(Y2/3W1/3)O3-PZT, Pb(Mn1/3Sb2/3)O3-PZT, Pb(Mg1/3Nb2/3)O3-Pb(Ni1/3 Nb2/3)O3-PZT, Pb(Ni1/2W1/2)O3-Pb(Mn1/3Nb2/3)O3-PZT, and PZT-PMnSbN, [4, 5, 7¨C11] have been synthesized by modifications or substitutions to satisfy the requirements of practical applications of piezoelectric transformer. In ceramics manufacturing technology, piezoelectric PZT system ceramics compositions are mostly near the tetragonal-rhombohedral (T-R) morphotropic phase boundary (MPB). The electromechanical response of these ceramics is known to be most pronounced at the MPB. So, there have been many investigations on the coexistence of two phases near MPB in PZT system [3]. The reports suggested the existence of a range of compositions where both tetragonal and rhombohedral phases are thermodynamically stable [7, 12]. In this study, 0.9Pb(ZrxTi1£¿x)O3-0.07Pb(Mn1/3Nb2/3)O3-0.03Pb(Sb1/2Nb1/2)O3 (PZT-PMnN-PSN) ceramics in the vicinity of MPB were investigated according to the Zr/Ti ratio content. The purpose of this work is to study structure and ferroelectric and piezoelectric properties in the vicinity of the MPB in detail. %U http://www.hindawi.com/journals/amse/2014/821404/