High piezoelectric coefficient of single domain Mn-doped NBT-6%BT single   crystals
  We report a study of properties of Mn-doped NBT-6%BT single crystals. We show that tetragonal single domain states can be stabilized by poling along a [001] direction. For carefully prepared crystals, the piezoelectric coefficient d33 can reach 570 pC/N. When poled along non-polar directions, the crystals exhibit ferroelectric domain structures consistent with tetragonal micron-sized domains, as revealed by optical observation and Raman spectroscopy. The multidomain crystals have lower d33 values, 225 and 130 pC/N for [011] and [111]-oriented crystals respectively. This trend is commented on from a domain-engineering perspective. 
Mael Guennou, Maxim Savinov, Jan Drahokoupil, Haosu Luo, Jirka Hlinka
cond-mat.mtrl-sci