CAREER: Probing the Nature of Coupled Ground States in Single Crystals of Magnetoelectric Perovskite Oxides

职业：探索磁电钙钛矿氧化物单晶中耦合基态的性质

• 批准号: 0449969
• 负责人: Prasenjit Guptasarma
• 金额: $ 50万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0449969&HistoricalAwards=false
• 关键词: CAREER; Probing; Nature; Coupled; Ground

This Faculty Early Career Award supports a project to synthesize and study a new class of materials called magnetoelectric multiferroics.. These materials may find future applications in spin-based electronic devices. In addition, with their nearby electric and magnetic dipole resonances in the frequency domain magnetoelectrics have the potential for realizing intrinsic far-infrared negative index materials (NIM). New magnetoelectric materials will be grown from a floating zone as bulk single crystals and in other forms. Lattice, magnetic, and, electronic structure as well as magnetic properties will be studied over a wide temperature range from ultra-low temperatures to above room temperature using an array of probes, some being accessed through collaborations. These include x-ray diffractometry, magnetometry, ultrasonic propagation and neutron diffraction. These studies will lead to the elucidation of detailed electronic phase diagrams. Additional studies at national synchrotron facilities will be undertaken to increase our understanding of the existence of magnetism in these highly insulating compounds. Charge and spin dynamics at femtosecond time scales will be studied using ultrafast time-resolved MOKE and Raman techniques. A new integrated curriculum in Solid State Physics will be implemented using an innovative laboratory, and students from this course will later obtain internships at local industries. AP Physics teachers from surrounding schools, along with their students, will participate in research activities. Through a partnership with the university's College for Kids program middle and high school students from under-represented groups will be provided stipends to participate in a High School Scholars summer workshop in the Physical Sciences. In addition a program will be created for the Science Bag, a highly popular Friday night magic-show style lecture tradition at the institution, open to the Milwaukee community.%%%A ferroelectric material is generally an electrical insulator that under certain conditions can spontaneously separate its positive and negative charges and thereby develop what is call an "electric dipole moment." This is similar to a bar magnet. However, instead of exhibiting a magnetic field, this "bar" exhibits an electric field. Ferroelectric materials are not usually magnetic. Independently, both magnetic materials and ferroelectric materials find extensive use in modern digital recording media and in memory devices. This Faculty Early Career Award supports a project to investigate new phases of a class of materials called magnetoelectric multiferroics. These materials are found to display both magnetism and ferroelectricity in the same material. Under certain conditions, the application of a voltage could change - or even reverse - the direction of spontaneous magnetization (i.e. an electrical voltage could cause a change in the direction of the magnetic "North pole") in the crystal. The magnetization of a material depends upon a quantity called "spin." Thus these materials may find future applications in electronic devices that depend on the "spin" rather than the electronic charge. New magnetoelectric materials will be grown in bulk single crystals and other forms. These new materials will be studied by a wide variety of experimental techniques elucidate their properties. These studies will deepen the understanding of both magnetism and ferroelectricity. A new integrated curriculum in Solid State Physics will be implemented using an innovative laboratory, and students from this course will later obtain internships at local industries. AP Physics teachers from surrounding schools, along with their students, will participate in research activities. Through a partnership with the university's College for Kids program middle and high school students from under-represented groups will be provided stipends to participate in a High School Scholars summer workshop in the Physical Sciences. In addition a program will be created for the Science Bag, a highly popular Friday night magic-show style lecture tradition at the institution, open to the Milwaukee community.

这个教师早期职业奖支持一个项目，以合成和研究一类新的材料称为磁电多铁性。这些材料可能会在基于自旋的电子器件中找到未来的应用。此外，由于其附近的电和磁偶极共振在频域磁电具有实现本征远红外负折射率材料（NIM）的潜力。新的磁电材料将从浮区生长为大块单晶和其他形式。晶格，磁性和电子结构以及磁性将在从超低温到室温以上的广泛温度范围内使用探针阵列进行研究，其中一些是通过合作访问的。这些方法包括X射线衍射、磁力测定、超声波传播和中子衍射。这些研究将导致详细的电子相图的阐明。将在国家同步加速器设施进行更多的研究，以增加我们对这些高度绝缘化合物中存在磁性的理解。飞秒时间尺度下的电荷和自旋动力学将使用超快时间分辨MOKE和拉曼技术进行研究。一个新的固态物理综合课程将使用一个创新的实验室实施，从这门课程的学生以后将获得在当地行业实习。来自周边学校的AP物理教师，沿着他们的学生，将参加研究活动。通过与该大学的儿童学院项目的合作，将为来自代表性不足群体的初中和高中学生提供奖学金，让他们参加物理科学方面的高中学者夏季研讨会。此外，还将为科学袋创建一个项目，这是该机构非常受欢迎的周五晚上魔术表演风格的讲座传统，向密尔沃基社区开放。铁电材料通常是电绝缘体，其在某些条件下可以自发地分离其正电荷和负电荷，从而产生所谓的“电偶极矩”。“这就像一块磁铁。 然而，这个“棒”并没有表现出磁场，而是表现出电场。铁电材料通常不具有磁性。独立地，磁性材料和铁电材料在现代数字记录介质和存储器件中得到广泛使用。这个教师早期职业奖支持一个项目，以调查一类称为磁电多铁性材料的新阶段。发现这些材料在同一材料中显示磁性和铁电性。 在某些条件下，施加电压可能会改变甚至逆转晶体中自发磁化的方向（即电压可能会导致磁“北极”方向的变化）。材料的磁化强度取决于一个叫做“自旋”的量。因此，这些材料可能会在依赖于“自旋”而不是电荷的电子器件中找到未来的应用。新的磁电材料将以大块单晶和其他形式生长。这些新材料将通过各种各样的实验技术来研究，以阐明它们的性质.这些研究将加深对磁性和铁电性的理解。一个新的固态物理综合课程将使用一个创新的实验室实施，从这门课程的学生以后将获得在当地行业实习。来自周边学校的AP物理教师，沿着他们的学生，将参加研究活动。通过与该大学的儿童学院项目的合作，将为来自代表性不足群体的初中和高中学生提供奖学金，让他们参加物理科学方面的高中学者夏季研讨会。此外，还将为科学袋创建一个项目，这是该机构一个非常受欢迎的周五晚上魔术表演风格的讲座传统，向密尔沃基社区开放。