A series of new solid solutions, (1 − x)PbTiO₃-xBi(Zn_2/3Ta_1/3)O₃ (0 < x < 0.2), have been synthesized, which show abnormally enhanced negative thermal expansion. The results of synchrotron X-ray diffraction reveal that with the increase in the dopant of Bi(Zn_2/3Ta_1/3)O₃ in the PbTiO₃ system, the increase in spontaneous polarization displacement could improve the negative thermal expansion behavior due to the spontaneous volume ferroelectrostriction (SVFS) effect. The STEM images show that PbTiO₃-Bi(Zn_2/3Ta_1/3)O₃ exhibits stronger polarization than PbTiO₃, which reveals a greater deviation. Moreover, the STEM images show that the element Ta has larger spontaneous polarization displacement than other B-site atoms. Furthermore, density functional theory calculations confirm the enhancement of hybridization between the A-site cations and oxygen upon the introduction of Bi(Zn_2/3Ta_1/3)O₃. All the above pieces of evidence indicate that the interplay between the cations and oxygen plays a key role in the enhancement of negative thermal expansion.

中文翻译：

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（1-x）PbTiO3-xBi（Zn2 / 3Ta1 / 3）O3中负热膨胀增强的证据

合成了一系列新的固溶体（1- x）PbTiO ₃ - x Bi（Zn _2/3 Ta _1/3）O ₃（0 < x <0.2），其负热膨胀异常增强。同步加速器X射线衍射结果表明，随着PbTiO ₃体系中Bi（Zn _2/3 Ta _1/3）O ₃掺杂量的增加，自发极化位移的增加可以改善负热膨胀行为。自发性铁电收缩（SVFS）效应。STEM图像显示PbTiO ₃ -Bi（Zn _2/3Ta _1/3）O _3的极化强度比PbTiO _3的极化强度大。此外，STEM图像显示元素Ta具有比其他B位原子更大的自发极化位移。此外，密度泛函理论计算证实了引入Bi（Zn _2/3 Ta _1/3）O ₃后A位阳离子与氧之间杂化作用的增强。以上所有证据表明，阳离子和氧之间的相互作用在负热膨胀的增强中起关键作用。