Heat capacity upgrade for PPMS

PPMS热容量升级

• 批准号: 359451-2008
• 负责人: Cadogan, John
• 金额: $ 5.32万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363789
• 关键词: Heat; capacity; upgrade; PPMS

Our research work focuses on the crystallographic and magnetic properties of a variety of materials incorporating the Rare Earth elements. Intermetallic Rare Earth compounds already provide the World's strongest permanent-magnets and will be the basis for the World's next generation of refrigerant materials. Rare Earth elements are also an essential component of the high-temperature superconductors. We are interested in the fundamental magnetism of Rare Earth compounds. What are their magnetic structures ? Why do these particular structures form and why do they sometimes change when one changes external parameters such as temperature and magnetic field ?     If we are to develop a comprehensive understanding of the intrinsic magnetic behaviour of such strategically important materials we must be able to characterise fully the changes observed in the magnetic behaviour. In other words, how much energy is associated with the various fundamental interactions whose complex interplay determines the intrinsic magnetic behaviour ?  Heat capacity is a fundamental thermodynamic parameter which is a direct measure of how much energy is lost or gained by a compound as it undergoes a changes in its crystal or magnetic structure.                Accurate knowledge of the temperature dependence of Heat Capacity can be used to detect changes and also understand the nature of those changes, We plan to investigate a variety of important Rare Earth compounds using Heat Capacity measurements, in conjunction with other data (magnetisation, Mossbauer spectroscopy, neutron diffraction....).

我们的研究工作主要集中在包含稀土元素的各种材料的晶体学和磁性。稀土金属间化合物已经提供了世界上最强的永磁体，并将成为世界下一代制冷材料的基础。稀土元素也是高温超导体的重要组成部分。我们对稀土化合物的基本磁性感兴趣。它们的磁性结构是什么？为什么这些特殊的结构会形成，为什么当外界参数如温度和磁场发生变化时，它们有时会发生变化？ 如果我们要全面了解这种具有重要战略意义的材料的固有磁性，我们必须能够准确地观察到磁性行为的变化。换句话说，有多少能量与各种基本相互作用有关，这些相互作用的复杂相互作用决定了内禀磁行为？ 热容是一个基本的热力学参数，它是一个化合物在其晶体或磁性结构发生变化时损失或获得多少能量的直接量度。 热容量的温度依赖性的准确知识可以用来检测变化，也可以理解这些变化的性质，我们计划使用热容量测量，结合其他数据（磁化强度，穆斯堡尔谱，中子衍射......）研究各种重要的稀土化合物。