Can relaxor piezoelectric materials outperform PZT?

This paper reviews the Pb(B'B")O/sub 3/-PbTiO/sub 3/ piezoelectric material system. Among the Pb(B'B")O/sub 3/-PbTiO/sub 3/ materials, Pb(Sc/sub 1/2/Nb/sub 1/2/)O/sub 3/-Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PSN-PMN-PT) ceramic material exhibits excellent piezoelectric properties near the MPB, such as k/sub p/>70%, k/sub t/>54%, k/sub 33/>77%, d/sub 33/>500 pC/N, and Tc=160-260/spl deg/C. The ceramic has superior piezoelectric properties as compared with conventional PZT ceramics, which so far have been thought to be the best binary piezoelectric ceramic materials. One of the big advantages of relaxor-PT systems compared with PZT is the ease with which single crystals of the MPB composition can be grown. These single crystals generally have superior properties compared with the ceramics if the appropriate axis is utilized. The advantages and disadvantages of the PSN-PMN-PT material and other Pb(B'B")O/sub 3/-PbTiO/sub 3/ systems are compared with PZT.