In situ TEM observation on the ferroelectric‐antiferroelectric transition in Pb(Nb,Zr,Sn,Ti)O 3 /ZnO
In situ TEM observation on the ferroelectric‐antiferroelectric transition in Pb(Nb,Zr,Sn,Ti)O 3 /ZnO
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DOI：
10.1111/jace.18148
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发表时间：
2021-10
影响因子：
3.9
通讯作者：
Binzhi Liu;Ling Li;Shantao Zhang;Lin Zhou;X. Tan
中科院分区：
文献类型：
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作者：
Binzhi Liu;Ling Li;Shantao Zhang;Lin Zhou;X. Tan
（1-x）Pb0.99{Nb0.02[（Zr0.57Sn0.43）0.937Ti0.063]0.98}O3（PNZST）/xZnO陶瓷复合材料最近被报道由于基体晶粒的铁电-反铁电转变而在人体温度附近表现出异常高的热释电系数。本文用原位加热透射电镜（TEM）对x = 0.1和0.4的两种复合材料进行了对比研究。结果验证了在x = 0.1的复合材料中，在室温下邻近ZnO颗粒的PNZST晶粒中存在应变场和稳定的铁电相。在加热过程中，铁电基体颗粒转变为反铁电相，从而产生热释电效应。在x = 0.4的复合物中，高角度环形暗场成像结合能量色散X射线光谱揭示了ZnO和Zn 2SnO 4的存在。Zn 2SnO 4的形成表明PNZST基质颗粒中的Sn被选择性地提取，并且钙钛矿相已经发生分解。观察到的细颗粒形式的分解产物，以促进反铁电相的成核和限制在加热过程中的相边界的运动。大量的ZnO和Zn 2SnO 4和PNZST钙钛矿相的分解被认为是负责在x = 0.4的复合材料的热释电系数低得多。
Ceramic composites of (1‐x)Pb0.99{Nb0.02[(Zr0.57Sn0.43)0.937Ti0.063]0.98}O3(PNZST)/xZnO were recently reported to exhibit exceptionally high pyroelectric coefficients near human body temperature due to the ferroelectric‐antiferroelectric transition of the matrix grains. In the present work, a comparative study is conducted on two composites ofx= 0.1 and 0.4 with in situ heating transmission electron microscopy (TEM). The results verify the presence of strain field in the PNZST grain adjacent to a ZnO particle and the stabilized ferroelectric phase at room temperature in the composite ofx= 0.1. During heating, the ferroelectric matrix grain transforms to the antiferroelectric phase, contributing to the pyroelectric effect. In the composite ofx= 0.4, high‐angle annular dark‐field imaging combined with energy‐dispersive X‐ray spectroscopy reveal the existence of both ZnO and Zn2SnO4. The formation of Zn2SnO4indicates that Sn in the PNZST matrix grain is selectively extracted, and decomposition of the perovskite phase has taken place. The decomposition products in the form of fine particles are observed to facilitate the nucleation of the antiferroelectric phase and restrict the motion of the phase boundary during heating. The larger amount of ZnO and Zn2SnO4and the decomposition of the PNZST perovskite phase are suggested to be responsible for the much lower pyroelectric coefficient in thex= 0.4 composite.