Optical studies of rare-earth crystal-field excitations in manganites and laser materials/Études optiques du champ cristallin dans les manganites et matériaux laser

锰酸盐和激光材料中稀土晶体场激发的光学研究/âtudes optiques du champ cristallin dans les manganites et matériaux Laser

• 批准号: 350-2012
• 负责人: Jandl, Serge
• 金额: $ 2.84万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568116
• 关键词: Optical; studies; rare; earth; crystal

Optical techniques such as light scattering, photoluminescence and infrared interferometry are useful to develop fundamental science and to explain microsopic interactions in solids. We use these techniques to better understand the fundamental physical properties of the following important recent high tech materials : a)- various multiferoics (rare-earth manganites and vanadates) in which magnetism and ferroelectricity, that have led to most important applications, coexist with a pronounced interplay. In these materials an electric polarization is actuated by a magnetic field and a magnetization is triggered by an electric field. They are of great application potential leading for instance to eight-state new memory devices, ferroelectric field-effect transistors and electric field controlled magnetic components. b)- solid state lasers in which interacting rare-earth ion pairs are formed (e.g. Yb-Yb ions in Yb doped NdVO4). Such pairs are at the origin of intrinsic bistability for optical switches and optical memories. They are also a source of cooperative emission doubling the infrared emission of the isolated Yb ion in green-blue light. In our studied materials, rare earth ions (Pr, Nd, Sm...) are incorporated. We get samples from four internationally recognized groups for the quality of their crystal growing expertise. Light scattering and infrared spectroscopy constitute our tools to detect the ionic vibrations (phonons), the magnetic excitations (magnons) and the energy levels of the 4f rare-earth electrons. These excitations and levels constitute local probe to detect the various electrical and magnetic interactions (electron-electron, electron-ion and ion-ion). Using quantum mechanics formalism, we then model the interactions that we tune and modify as a function of temperature, doping and applied magnetic and electric fields. We aim to develop a basic comprehension of these strategic materials properties in order to orient the crystal growers in generating new strategic compounds that would enhance the essential particularities of the rare-earth based multiferroics and laser materials for new high tech developments.

光散射、光致发光和红外干涉测量等光学技术对于发展基础科学和解释固体中的微观相互作用非常有用。我们使用这些技术来更好地了解以下重要的最新高科技材料的基本物理特性： a)- 各种多铁性材料（稀土锰酸盐和钒酸盐），其中磁性和铁电性导致了最重要的应用，并以明显的相互作用共存。在这些材料中，电极化由磁场驱动，磁化由电场触发。它们具有巨大的应用潜力，例如八态新型存储器件、铁电场效应晶体管和电场控制磁性元件。 b)- 固态激光器，其中形成相互作用的稀土离子对（例如，掺镱 NdVO4 中的 Yb-Yb 离子）。这些对是光开关和光存储器固有双稳态的根源。它们也是协同发射源，使绿蓝光中孤立的 Yb 离子的红外发射加倍。 在我们研究的材料中，掺入了稀土离子（Pr、Nd、Sm...）。我们从四个国际公认的团体获取样品，因为他们的晶体生长专业知识质量很高。光散射和红外光谱构成了我们检测离子振动（声子）、磁激发（磁振子）和 4f 稀土电子能级的工具。这些激发和能级构成局部探针来检测各种电和磁相互作用（电子-电子、电子-离子和离子-离子）。然后，我们使用量子力学形式，对我们根据温度、掺杂以及施加的磁场和电场进行调整和修改的相互作用进行建模。我们的目标是对这些战略材料特性有一个基本的理解，以便指导晶体生长者生成新的战略化合物，从而增强稀土基多铁性材料和激光材料的基本特性，以促进高新技术的发展。