RUI: Mossbauer and Magnetization studies of Fe(1-x)Co(x)Z (Z = Si, Ge, and Sn) and Synthesis of Carbon Based Fullerenes using Laser Ablation

非技术性描述：NSF的资金将在三年内支持本科生的几项研究。 这些研究将探索合成和检测半金属的新方法。 半金属是导体时，载体电子是一个自旋取向，但绝缘体的电子相反的方向。这项研究将有助于开发新的矩阵中使用的基质辅助激光解吸电离（MALDI）技术，在搜索一些以前没有观察到的母阴离子。 半金属已显示出在未来电子器件开发中发挥重要作用的前景。 所提出的新方法涉及在惰性气氛中的受控冷凝室中使用半金属成分的激光蒸发。 由于激光烧蚀已被证明是产生富勒烯、内嵌金属富勒烯和类似笼状分子的有效技术，因此将在这种支持的帮助下寻找新的笼状分子物种。 除了可能合成新材料外，这些研究还为物理和化学本科生提供了实践经验的机会，他们希望通过教学和研究的综合方法来提高学生对物理，化学和材料科学的兴趣。在公认的Fe（1-x）Co（x）Si化合物中，存在特定的x范围，在该范围内材料被认为是半金属。在这些化合物中，半金属性的出现伴随着铁磁性。 激光蒸发技术将用于合成半金属Fe（1-x）Co（x）Z族（其中Z = Si、Ge和Sn），目的是通过替换来自周期表的同一列的元素来探索Z位元素的尺寸对该族的性质的影响。 Fe（1-x）Co（x）（Ge，Sn）化合物尚未观察到。 激光烧蚀技术将用于搜索笼状分子，这些分子已被计算为能量稳定的，如C12 B24 N24。 升华技术，伴随着激光烧蚀在加热区梯度将被用来分离的各种混合金属化合物，其中拉曼光谱在氮气和计算可以用于结构测定在田纳西大学。 此外，将研究各种基质以观察氢化富勒烯的母体阴离子。 本科生将在新技术，如激光烧蚀和飞行时间质谱的实践经验。

NON-TECHNICAL DESCRIPTION: Funding from NSF will support several studies over a three year period in an undergraduate setting. These studies will explore new ways of synthesizing and examining half-metals. Half metals are conductors when the carrier electrons are one spin orientation, but are insulators to electrons of the opposite orientation. This research will be assisted by the development of new matrices to be used in the matrix assisted laser desorption ionization (MALDI) technique in search of some parent anions that have not been previously observed. Half-metals have shown promise to play an important role in the development of future electronic devices. The proposed new method involves the use of laser vaporization of the half-metal constituents in a controlled condensation chamber in an inert atmosphere. As laser ablation has proven to be an effective technique of generating fullerenes, endohedral metallofullerenes, and similar caged molecules, a search for new caged molecular species will be undertaken with the help of this support. In addition to the possible synthesis of new materials, these studies offer the opportunities of hands-on experience for physics and chemistry undergraduate students, which they hope will serve to increase the students' interest in physics, chemistry, and material science in an integrative approach of teaching and research.TECHNICAL DETAILS: In the well-established Fe(1-x)Co(x)Si compounds there are specific ranges of x for which the material is considered to be a half-metal. The appearance of half metallicity is accompanied by ferromagnetism in these compounds. The laser vaporization technique will be used to synthesize the family of half metals Fe(1-x)Co(x)Z (where Z = Si, Ge, and Sn) with the goal of exploring the effect of the size of the Z-site elements by substituting elements from the same column of the periodic table on the properties of this family. Fe(1-x)Co(x)(Ge, Sn) compounds have not yet been observed. The laser ablation technique will be utilized in search of caged molecules that have been calculated to be energetically stable such as C12B24N24. Sublimation techniques that accompany the laser ablation in a heated zone gradient will be used to separate the various mixed metal compounds where Raman spectroscopy under nitrogen and computations can be employed for structural determination at the University of Tennessee. Furthermore, various matrices will be investigated to observe the parent anions of hydrogenated fullerenes. Undergraduate students will have hands-on experience in new technologies such as laser ablation and time-of-flight mass spectrometry.