CAREER: Structure Property Relationships in BiFeO3: A Defect Chemistry Approach

职业：BiFeO3 中的结构性质关系：缺陷化学方法

• 批准号: 0547134
• 负责人: Jon-Paul Maria
• 金额: $ 40万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0547134&HistoricalAwards=false
• 关键词: CAREER; Structure; Property; Relationships; BiFeO3

NON-TECHNICAL DESCRIPTION: A new methodology allowing composition control of thin film complex oxides with a volatile constituent will be developed. This technique will be demonstrated in bismuth ferrite, which is a crystalline solid having material properties of current technological interest. This new processing approach will allow dramatic reduction composition-related defects at the nanoscale, and in doing so, provide for dramatic improvements in the electrical properties. Of premier interest is the ability of bismuth ferrite to couple electrical and magnetic fields: this capability is widely regarded as the cornerstone of a new generation of multifunctional sensing, actuating, and data storage devices. For example, devices offering unprecedented and simultaneous sensing of electrical, acoustic, and magnetic fields will be enabled, and are extremely attractive for applications such as remote surveillance. These opportunities can be fully harnessed only if the improvements offered by this research are realized. Through the duration of this program, a minimum of one graduate student and two undergraduate students will be active participants, and each summer semester, this program will support a Materials Science educational outreach activity. This activity will involve learning workshops for K-12 science teachers, which focus on empowering K-12 educators to incorporate the Principles of Materials Science, specifically at the nanoscale, to their curriculum.TECHNICAL DETAILS: The proposed program explores fundamental relationships between defect chemistry, crystalline structure, and the electrical properties of ferroelectric thin films. The cornerstone of this investigation involves a novel thin film processing methodology controlling cation stoichiometry and point defects in BiFeO3 through gas-phase equilibrium. This represents a fundamental contribution to thin film processing science since nearly all commercial and military electronic materials rely on property optimization in part through defect equilibrium engineering. A similarly sophisticated capacity has not been developed for electroceramic thin films, thus a major opportunity in thin film property engineering remains untapped. The proposed synthesis technique will enable this optimization in numerous systems holding promise for dramatic property improvement, and insight into defect-related phenomena. In the course of their research, the participating graduate and undergraduate students will develop a cutting-edge gas-phase/condensed-phase equilibrium method for actively tuning defect equilibria. In doing so, they will identify defect equilibria - property relationships in thin films, which represents an important advancement in Materials Science, especially at the nanoscale, where the impact of defects becomes more pronounced.

非技术描述：将开发一种新的方法，允许控制具有挥发性成分的薄膜复合氧化物的成分。该技术将在铁氧体铋中得到演示，铁氧体是一种结晶固体，具有当前技术兴趣的材料特性。这种新的加工方法将能够在纳米尺度上显着减少与成分相关的缺陷，从而显着改善电性能。最令人感兴趣的是铁氧体铋耦合电场和磁场的能力：这种能力被广泛认为是新一代多功能传感、驱动和数据存储设备的基石。例如，能够提供前所未有的电、声和磁场同步感测的设备将被启用，并且对于远程监控等应用极具吸引力。只有实现本研究提供的改进，才能充分利用这些机会。在该计划期间，至少有一名研究生和两名本科生将积极参与，每个夏季学期，该计划将支持一项材料科学教育推广活动。这项活动将包括为 K-12 科学教师举办学习研讨会，重点是让 K-12 教育工作者将材料科学原理（特别是纳米尺度的材料科学原理）纳入他们的课程中。技术细节：拟议的计划探讨了缺陷化学之间的基本关系、铁电薄膜的晶体结构和电性能。这项研究的基石涉及一种新颖的薄膜加工方法，通过气相平衡控制 BiFeO3 中的阳离子化学计量和点缺陷。这代表了对薄膜加工科学的根本性贡献，因为几乎所有商业和军用电子材料都部分依赖于通过缺陷平衡工程进行性能优化。电陶瓷薄膜尚未开发出类似的复杂能力，因此薄膜特性工程的一个重大机会仍未开发。所提出的合成技术将在许多系统中实现这种优化，有望显着改善性能并洞察缺陷相关现象。在研究过程中，参与的研究生和本科生将开发一种用于主动调整缺陷平衡的尖端气相/凝聚相平衡方法。在此过程中，他们将确定缺陷平衡——薄膜中的属性关系，这代表了材料科学的重要进步，特别是在纳米尺度上，缺陷的影响变得更加明显。