Magnetoelectricity and Multiferroic behaviour in Tungsten Bronze Oxides

近年来，对具有铁电和磁有序的材料的研究有了显著的复苏。这项研究包括磁电材料（那些表现出任何形式的磁性和电序之间的耦合）和多铁性材料（那些表现出铁电性、铁磁性和铁弹性三种铁性质中的两种或两种以上的材料）。特别令人感兴趣的是表现出铁磁性和铁磁性行为的多铁性材料，因为它们为磁场和电场与物质的相互作用提供了令人兴奋的新可能性。铁电性和铁磁性在材料或器件中的耦合将提供独特的多功能行为，使21世纪的许多新器件的设计成为可能。多功能行为领域是国家和国际技术路线图和政府计划的热门领域之一。这是因为真正的多功能系统广泛适用于国防和医疗等工业部门。本研究的目的是表征含有不同数量磁活性物质的铁电钨青铜氧化物，以期开发一种设计磁电和多铁性材料的方法。最终，一系列表现出磁电和多铁性行为的新材料将被生产出来，以进一步研究电和磁有序之间的耦合机制，并为未来的应用和设备发展提供帮助。

In recent years there has been a dramatic resurgence of research in materials exhibiting ferroelectric and magnetic ordering. This research has included both magnetoelectric materials (those that exhibit any form of coupling between magnetic and electric order) and multiferroics (those which exhibit two or more of the 3 ferroic properties of ferroelectricity, ferromagnetism and ferroelasticity). Of particular interest are multiferroic materials exhibiting ferromagnetic and ferromagnetic behaviour as these offer exciting new possibilities for the interaction of magnetic and electric fields with matter. The coupling of ferroelectricity and ferromagnetism in a material or device would provide unique multifunctional behaviour enabling design of a host of new devices for the 21st Century. The area of multifunctional behaviour is one of vogue in national and international technology roadmaps and government plans. This is because of the widespread applicability of truly multifunctional systems in industrial sectors such as defence and medicine. The aim of this study is to characterise ferroelectric tungsten bronze oxides containing varying amounts of magnetically active species with a view to developing a methodology for designing magnetoelectric and multiferroic materials. Ultimately, a new range of materials which exhibit magnetoelectric and multiferroic behaviour will be produced to allow further investigation of the coupling mechanisms between electric and magnetic ordering and for future development of applications and devices.