'A' cation control of perovskite properties
'A' cation control of perovskite properties
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DOI：
10.1016/s1463-0184(02)00054-0
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发表时间：
2002-09-01
期刊：
影响因子：
--
通讯作者：
Attfield, JP
中科院分区：
文献类型：
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作者：
Attfield, JP
许多ABO(3)钙钛矿的材料性质主要由B阳离子决定，但受A位阳离子的调节。值得注意的例子是铁电钛酸盐、磁阻锰酸盐和层状A(2)BO(4)型超导铜酸盐。通过考虑A阳离子的大小和电荷，可以通过一种简单的离子方法来描述A阳离子对这些性质的控制。平均A离子半径（相当于传统的钙钛矿容差系数）和描述离子半径不匹配的尺寸方差可以很好地近似地控制尺寸。近年来的研究表明，后一项非常重要；铁电、铁磁、超导和结构转变温度都随尺寸变化呈线性变化。方差与大小图定义了“化学窗口”，使属性变化能够有效地显示出来。还证明了锰钙钛矿中相分离现象的变异控制。相反，在锰酸盐和铜酸盐中，A阳离子的电荷变化并不重要。2003爱思唯尔科学有限公司版权所有。
The materials properties of many ABO(3) perovskites result primarily from the B cations, but are tuned by the cation(s) at the A sites. Notable examples are ferroelectric titanates, magnetoresistive manganites, and layered A(2)BO(4) type superconducting cuprates. The A cation control of these properties can be described through a simple ionic approach by considering the sizes and charges of the A cations. The size control is approximated well by the mean A cation radius, equivalent to the traditional perovskite tolerance factor, and the size variance which describes the mismatch in ionic radii. Studies in recent years have shown that the latter term is extremely significant; ferroelectric, ferromagnetic, superconducting and structural transition temperatures all vary linearly with the size variance. A variance vs. size plot defines the 'chemical window' which enables property variations to be displayed usefully. The variance control of phase separation phenomena in manganite perovskites has also been demonstrated. In contrast, the A cation charge variance is shown to be unimportant in manganites and cuprates. (C) 2003 Elsevier Science Ltd. All rights reserved.