• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Advanced Functional Materials >Direct Observation of Core-Shell Structures in Individual Lead Titanate Ferroelectric Nanostructures by Tip-Enhanced Refractive Index Mapping
【24h】

Direct Observation of Core-Shell Structures in Individual Lead Titanate Ferroelectric Nanostructures by Tip-Enhanced Refractive Index Mapping

机译：通过尖端增强折射率映射直接观察钛铅铁电纳米结构中的核-壳结构

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Ferroelectrics undergo a size-driven phase transition at the nanoscale below which the spontaneous polarization, their defining property, irrevocably ceases. This threshold often referred to as the superparaelectric limit has tremendous technological relevance in an era of progressing integration. Just as the balance of short-range elastic and long-range electrostatic ordering in bulk, the critical size depends on temperature. Room-temperature tip-enhanced Raman spectroscopy (TERS) imaging of individual lead titanate (PbTiO3) nanoislands is reported with a spatial resolution of approximate to 3 nm. Monitoring the spectral shift of the gold-tip enhanced luminescence, which depends on the local refractive index, images grains composing the nanoislands. The wavelength of the enhanced luminescence shifts between the grains and their boundaries indicating the predicted core-shell structure of ferroelectric and paraelectric phase. The shear force configuration rules out the distance dependence of capacitive plasmonic coupling between tip and substrate as the origin of the observed shift. As the reported temperature-changes in nonresonant TERS do not account for noticeable thermal effects, the underlying, even though weak, tip-enhanced Raman spectrum of the grain core reflects PbTiO3 close to the ferroelectric-to-paraelectric phase transition which is primarily related to the finite size of the grains.
机译：铁电体在纳米级经历了尺寸驱动的相变，在该相变以下，自发极化，其定义特性不可撤销地终止。这个阈值通常被称为超顺电极限，在不断发展的集成时代中具有巨大的技术意义。正如散装的短程弹性和远程静电排序的平衡一样，临界尺寸也取决于温度。报告了单个钛酸铅（PbTiO3）纳米岛的室温尖端增强拉曼光谱（TERS）成像，其空间分辨率约为3 nm。监测金尖端增强发光的光谱偏移（取决于局部折射率），可以对组成纳米岛的晶粒进行成像。增强的发光的波长在晶粒及其边界之间移动，表明预测的铁电和顺电相核-壳结构。剪切力配置排除了尖端和基底之间的电容性等离激元耦合的距离依赖性，而后者是观察到的位移的起源。由于所报告的非共振TERS中的温度变化并未说明明显的热效应，即使是弱的，尖端增强的晶粒核心拉曼光谱，其潜在的基础反射也反映了PbTiO3接近于铁电至顺电相变，这主要与晶粒的有限尺寸。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号