Institute of Physics, Opole University, Opole, 45-052, Poland.
J Phys Condens Matter. 2010 Jun 16;22(23):235902. doi: 10.1088/0953-8984/22/23/235902. Epub 2010 May 21.
We demonstrate that recent experimental data (Castel et al 2009 J. Phys.: Condens. Matter 21 452201) on the tungsten bronze compound (TBC) Ba(2)Pr(x)Nd(1-x)FeNb(4)O(15) can be well explained in our model predicting a crossover from ferroelectric (x = 0) to orientational (dipole) glass (x = 1), rather then relaxor, behavior. We show that, since a 'classical' perovskite relaxor like Pb(Mn(1/3)Nb(2/3))O(3) is never a ferroelectric, the presence of ferroelectric hysteresis loops in the TBC shows that this substance actually transits from ferroelectric to orientational glass phase with x growth. To describe the above crossover theoretically, we use the simple replica-symmetric solution for the disordered Ising model.
我们证明，最近关于钨青铜化合物（TBC）Ba(2)Pr(x)Nd(1-x)FeNb(4)O(15)的实验数据（Castel 等人，2009 年，J. Phys.：Condens. Matter 21，452201）可以很好地用我们的模型解释，该模型预测从铁电（x = 0）到取向（偶极）玻璃（x = 1）的转变，而不是弛豫体行为。我们表明，由于像 Pb(Mn(1/3)Nb(2/3))O(3) 这样的“经典”钙钛矿弛豫体从来不是铁电体，因此 TBC 中存在铁电滞后环表明该物质实际上随着 x 的增加从铁电相过渡到取向玻璃相。为了从理论上描述上述转变，我们使用无序伊辛模型的简单复制对称解。
