Ultrafine Magnetic Particles of Metals, Metal Borides, and Metal Oxides

这一材料化学领域的多学科项目由无机化学、生物无机化学和有机金属化学计划以及固体物理计划共同支持。合作的调查人员是堪萨斯州立大学的克里斯托弗·M·索伦森博士和肯尼斯·J·克拉本德博士，以及特拉华大学的乔治·C·哈迪帕纳伊斯博士。将继续研究超细磁性颗粒的合成和评价，目的是与块状样品相比，更多地了解这些颗粒的基本性质，开发合成、保护和控制颗粒尺寸和微观结构的方便方法，并更好地了解形成这些颗粒的过程的化学和物理。将研究一系列合成方法来制备尺寸在1-1000纳米范围内的金属、金属硼化物和金属氧化物颗粒。合成技术将包括在惰性气体下在冷基质中聚集金属原子和溅射。还将研究用硼氢化物还原金属离子、氢氧化物沉淀和消解以及气溶胶的热解。将探索用于控制颗粒大小的反胶束技术，还将研究在聚合物、沸石或Vycor玻璃等结构介质中捕获小颗粒的情况。磁性颗粒将从化学成分、形态、磁有序、磁矩、矫顽力和相变等方面进行彻底的表征。

This multidisciplinary project in the area of materials chemistry is jointly supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program and the Solid State Physics Program. The collaborating investigators are Dr. Christopher M. Sorensen and Dr. Kenneth J. Klabunde of Kansas State University and Dr. George C. Hadjipanayis of the University of Delaware. Research will continue on the synthesis and evaluation of ultrafine magnetic particles, with the goals of learning more about the fundamental properties of these particles compared to bulk samples, to develop convenient methods for synthesis, protection and control of particle sizes and microstructure, and to gain a better understanding of the chemistry and physics of the processes by which they are formed. A broad range of synthetic approaches to the preparation of metallic, metal boride and metal oxide particles in the size range of 1-1000 nm will be investigated. Synthetic techniques will include metal atom clustering in cold matrices under inert gases and sputtering. Also to be investigated are reduction of metal ions by borohydride, hydroxide precipitation and digestion, and pyrolysis of aerosols. Reversed micelle techniques will be explored for the control of particle sizes, and the trapping of small particles in structural media, such as polymers, zeolites or vycor glass, will be investigated also. Magnetic particles will be thoroughly characterized with respect to chemical composition, morphology, magnetic ordering, magnetic moment, coercivity, and phase transformations.