Functional and structural effects of layer periodicity in chemical solution-deposited Pb(Zr,Ti)O 3 thin films
Functional and structural effects of layer periodicity in chemical solution-deposited Pb(Zr,Ti)O 3 thin films
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化学溶液沉积Pb(Zr,Ti)O 3 薄膜层周期性的功能和结构效应
DOI：
10.1111/jace.15057
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发表时间：
2017
影响因子：
3.9
通讯作者：
Brewer S
中科院分区：
文献类型：
--
作者：
Brewer S
这项工作研究了化学溶液沉积的锆钛酸铅薄膜中结晶层的周期性和厚度对功能响应的作用，其中 Zr 和 Ti 梯度垂直于薄膜表面周期性交替。这些薄膜采用一系列层周期性和相似的总薄膜厚度进行处理，以便将层数和成分振荡与结构和功能响应变化联系起来。随着层周期性的增加，观察到对介电和铁电响应的外在贡献增加的趋势，但与对介电和铁电响应的内在贡献同时减少相反。透射电子显微镜揭示了各个结晶界面的面内晶体不连续性。具有较小周期性和更薄层的样品可能会受到晶粒尺寸细化和随后域尺寸减小的影响，从而限制了对响应的外在贡献。具有较大周期性的样品中的强烈成分振荡导致相图四方侧的深度波动，可能减少对响应的内在贡献。相反，压电响应力显微镜结果表明，具有较大周期性的样品中的大化学振荡也会导致更接近同形相边界，正如开关时的局部声软化所证明的那样，表明势场引起的相变。
This work investigates the role of crystallization layers’ periodicity and thickness on functional response in chemical solution‐deposited lead zirconate titanate thin films, with periodic, alternating Zr and Ti gradients normal to the surface of the film. The films were processed with a range of layer periodicities and similar total film thickness, in order to relate the number of layers and compositional oscillations to structural and functional response changes. Trends of increased extrinsic contributions to the dielectric and ferroelectric responses are observed with increasing layer periodicity, but are counterpointed by simultaneous reduction in intrinsic contributions to the same. Transmission electron microscopy reveals in‐plane crystallographic discontinuity at individual crystallization interfaces. Samples with smaller periodicity, and thus thinner layers, potentially suffer from grain size refinement and subsequent reduction in domain size, thereby limiting extrinsic contributions to the response. The strong compositional oscillations in samples with larger periodicity result in deep fluctuations to the tetragonal side of the phase diagram, potentially reducing intrinsic contributions to the response. Conversely, piezoresponse force microscopy results suggest that large chemical oscillations in samples with larger periodicity also result in closer proximity to the morphotropic phase boundary, as evidenced by local acoustic softening at switching, signaling potential field‐induced phase transitions.