PMN-PT弛豫铁电固溶体的定向凝固组织与结晶习性

Structure and Grain Growth Habit of Directional Solidification Ceramics of (1-x)Pb(Mg_(1/3)Nb_(2/3))O_3 - xPbTiO_3 (x=0.30, 0.33, 0.38) Relaxor Ferroelectric Solid Solutions

研究了(1-x)Pb(Mg_(1/3)Nb_(2/3))O_3-xPbTiO_3(简称PMN-PT或PMNT)系铁电固溶体在坩埚下降法定向凝固过程中的结晶与晶粒生长习性.结果表明,随着坩埚下降速度的加快和PbTiO_3含量的降低,陶瓷晶粒的择优生长方向由[111]逐渐向[110]转变。

This work describes the grain growth habit of the (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) (PMN-PT or PMNT) system ferroelectric solid solutions prepared by a directional solidification technique. The results show that the preferential direction of the grain growth depends not only on the composition of the melts, but also on the crucible pulling-down speed. For a fixed PMN/PT ratio, e.g. 62/38, higher speed of crucible pulling-down leads to a preferential grain growth orientation of [110], rather than the [111], which is usually reported in single crystal growth studies, whereas lower crucible pulling-down speed tends to produce [111] grain-orientation ceramics. When the crucible is pulled down at a certain rate, the preferential grain-growth orientation changes from [111] to [110] with reducing PbTiO(3) molar contents.