Grinberg Ilya, Rappe Andrew M
The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
Phys Rev Lett. 2007 Jan 19;98(3):037603. doi: 10.1103/PhysRevLett.98.037603.
We use first-principles density functional theory calculations to investigate the strongly nonlinear compositional trends in ferroelectric BiBO3-PbTiO3 solid solutions for a variety of cations on the perovskite B site. We demonstrate that previously tabulated crystal chemical parameters (extracted from other Pb-based perovskite alloys [Grinberg et al., J. Appl. Phys. 98, 094111 (2005)]) permit accurate prediction of cation displacements in these new Bi-Pb alloys. We find that observed transition temperatures in these materials are well correlated with computed polarization magnitudes. The presented model for coupling between compositional variation and cation displacements explains the highly nonlinear and often nonmonotonic dependence of the Curie temperature (T(C)) on composition observed in these solid solutions.
我们使用第一性原理密度泛函理论计算，研究了钙钛矿B位上多种阳离子的铁电BiBO3-PbTiO3固溶体中强烈的非线性成分趋势。我们证明，先前列表的晶体化学参数（从其他基于Pb的钙钛矿合金中提取[格林伯格等人，《应用物理杂志》98，094111（2005）]）能够准确预测这些新型Bi-Pb合金中的阳离子位移。我们发现，这些材料中观察到的转变温度与计算出的极化强度密切相关。所提出的成分变化与阳离子位移之间的耦合模型解释了在这些固溶体中观察到的居里温度（T(C)）对成分的高度非线性且通常非单调的依赖性。
