0548061 Li

1. CAREER: Investigation of the Growth Mechanism of Ruthenium Dioxide NanostructuresWenzhi Li, Florida International University, DMR 0548061 Low-dimensional RuO2 nanostructures hold a promising future in nanoelectronicsapplication due to their low resistivity and excellent thermal and chemical stabilities over a wide temperature range. The understanding of the growth mechanism of the RuO2 nanostructures is essential for controlling their growth and developing novel devices. We have studied the growth mechanism by combing experiment and electronic structure calculation. The experiment reveals that the O2 flow rate, concentration and pressure play significant roles in the formation of RuO2nanostructures, as show in the Figure. Our calculation confirms that RuO2has higher energy compared to RuO3 and RuO4. The less stable RuO3 (as compared to RuO4) is more suitable for nanorod growth and a rich O2 environment at the RuO2source is a preferable condition to grow RuO2nanorods. RuO2 nanostructures synthesized at various conditions. (a) Polygonal prisms with uniform width formed at low O2 flow rate, (b) top-view of nanorods with square-shaped hollow tips at high O2 flow rate, (c) hierarchical pine tree-liked structure formed at high pressure, and (d) flower-liked nanostructures formed at low O2 concentration.

2. Undergraduate Student Education and Research Training in Nanomaterial ScienceWenzhi Li, Florida International University, DMR 0548061 The PI has actively involved undergraduate students in his research. The students work closely with postdoctoral associates, graduate students, and the PI to receive extensive research training. Three undergraduate students have made significant contributions to research results which will be published in peer reviewed journals. To expose many undergraduate students to nanomaterials research, the PI has developed an advanced curriculum titled “Widely Applied Physics” which combines classroom lectures, invited presentations and lab demonstrations. Each year, about 20 undergraduate students attend this class to gain knowledge of nanosciene and technology. Undergraduate students from the PI’s “Widely Applied Physics” class are visiting the Advanced Materials Engineering Research Institute and Motorola Nanofabrication Facility at Florida International University.