Raman spectroscopy of Nd-doped BiFeO3 based ceramics and thin films

布拉格科学院介电学系主任Hlinka博士表示有浓厚的兴趣与谢菲尔德小组进行互动，并在2010年4月至6月期间成为为期3个月的客座教授，以建立尽可能强的合作。这项合作将极大地推动谢菲尔德蓬勃发展的拉曼活动，并在这样做的过程中，提高了英国在结构测定这一关键领域的知识基础。谢菲尔德的PI小组最近发现了一种新的AFE，基于Nd掺杂BiFeO 3（BNF）的PbZrO 3结构陶瓷。与利兹大学合作，不久将开始使用脉冲激光沉积技术开发掺钕BiFeO 3（BNF）薄膜。这项新计划的最初目标是确定AFE结构是否保留在薄膜中，以及在批量中观察到的结构相变作为温度和成分的函数是否仍然有效。我们已经建立了拉曼光谱是敏感的BNF系统内的结构变化，但这种新材料的主要问题是在光谱的详细解释。因此，访问奖学金的主要研究目标是：i）建立实验方案，从功能薄膜中获得高质量的紫外拉曼光谱; ii）利用Hlinka博士的丰富经验来帮助解释光谱。除拉曼研究外，PI小组将使用分析电子显微镜（EP/F006098/1，S.Miao）获得详细的结构信息。以这种方式，一个完整的理解BNF薄膜中的结构变化将被用来解释铁电和介电行为。除了这些科学目标，Hlinka博士将提供关于“在功能氧化物研究中使用振动光谱学”的教程，并将访问英国功能氧化物社区内的几个感兴趣的团体。

Dr Hlinka, Head of the Department of Dieletrics at the Academy of Science, Prague, has expressed a strong interest to interact with the Sheffield group and to establish the strongest possible collaboration by becoming a Visiting Professor for a period of 3 months between April-June 2010. This collaboration would hugely advance the burgeoning Raman activity at Sheffield and in doing so improve the knowledge base for the UK in this key area of structural determination. The group of the PI at Sheffield have recently discovered a new AFE, PbZrO3-structured ceramic based on Nd-doped BiFeO3 (BNF). In collaboration with the University of Leeds, the development of thin films of Nd-doped BiFeO3 (BNF) using pulsed laser deposition will shortly begin. The initial aims of this new programme will be to establish whether the AFE structure is retained within the film and whether the structural phase transitions observed in bulk as a function of temperature and composition remain valid. We have established that Raman spectroscopy is sensitive to the structural changes within BNF system but the main problem with such new materials is in the detailed interpretation of the spectra. The key research goals of the Visiting Fellowship are therefore to i) establish the experimental protocols to obtain high quality UV Raman spectra from thin functional films and ii) utilise the vast experience of Dr Hlinka to help interpret the spectra. In addition to the Raman study, the group of the PI will obtain detailed structural information using analytical electron microscopy (EP/F006098/1, S.Miao). In this manner, a complete understanding of the structural changes in BNF thin films will be obtained which will be utilised to interpret the ferroelectric and dielectric behaviour. In addition to these scientific goals, Dr Hlinka will give tutorials on the 'Use of Vibrational Spectroscopy in the Study of Functional Oxides' and will visit several interested groups within the UK Functional Oxide community.