Anomalous Curie temperature behavior of A-site Gd-doped BaTiO3 ceramics: The influence of strain
Anomalous Curie temperature behavior of A-site Gd-doped BaTiO3 ceramics: The influence of strain
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DOI：
10.1063/1.3563710
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发表时间：
2011-02-28
影响因子：
4
通讯作者：
Sinclair, Derek C.
中科院分区：
文献类型：
--
作者：
Ben, Liubin;Sinclair, Derek C.
根据钛空位机制Ba1-xGdxTi1-x/4O3，研究了A位Gd3+掺杂对BaTiO3铁电材料的c/a比、晶胞体积和居里温度的影响，并与La3+掺杂进行了比较。Gd掺杂样品的c/a比和晶胞体积大于相应的La掺杂样品，而T-c的下降速率仅接近8℃/at。Gd3+替代的百分比与24摄氏度/at相似。La~(3+)取代的百分比。这些趋势与基于离子半径和容忍系数的预期相反。这种反常行为归因于Ba2+和Gd3+离子之间A位上的离子尺寸失配(阳离子方差)效应，它在晶格中引起局部应变，抑制了c/a比和晶胞体积的下降，从而导致T-c下降的速度。(C)2011年美国物理研究所。[DOI：10.1063/1.3563710]
The influence of A-site Gd3+ doping on the c/a ratio, cell volume and Curie temperature (T-c) of ferroelectric BaTiO3 according to the titanium vacancy mechanism, viz., Ba1-xGdxTi1-x/4O3 has been investigated and compared to that of La3+-doping. The c/a ratio and cell volume of Gd-doped samples are larger than the equivalent La-doped samples and T-c decreases at a rate of only similar to 8 degrees C/at. % for Gd3+ substitution compared to similar to 24 degrees C/at. % for La3+ substitution. These trends are opposite to that expected based on ionic-radii and tolerance factor arguments. This anomalous behavior is attributed to an ion-size mismatch (cation variance) effect on the A-site between the Ba2+ and Gd3+ ions that induces local strain in the lattice that suppresses the reduction in the c/a ratio and cell volume, and as a consequence in the rate of decrease in T-c. (C) 2011 American Institute of Physics. [doi:10.1063/1.3563710]