CAREER: Synthesis and Characterization of One-Dimensional Chemical Nanostructures

Harvard University, Cambridge MA

Investigators

Abstract

The Advanced Materials Program in the Division of Chemistry makes this Career award to Harvard University to study one-dimensional chemical nanostructures. With this award, Professor Hongkun Park will study the synthesis of large-diameter Single Walled carbon Nanotubes (SWNTs) with controlled diameter and helicity by chemical vapor deposition using well-isolated catalyst nanoparticles with uniform size distributions. Scanned-probe microscopy (SPM) will be used to determine electromechanical properties and the coupling between global radial deformation and electron transport properties of these SWNTs. Synthesis of individual single-crystalline nanowires prepared from barium titanate and related compounds and their subsequent characterization by variable-temperature SPM will also be carried out with this award. The SPM to study ferroelectric and piezoelectric properties of nanowires should provide fundamental knowledge that governs the thermodynamics as well as the kinetics of phase transition and polarization switching. Electrostatic force microscopy will be used to 'read' and 'write' by measuring the local electric polarization on the nanowires. The PI, with the help of other faculty members, will give lectures in materials science and nanotechnology to middle school students as part of the "Early College Awareness Program" to attract students to science related studies and careers. Large-diameter Single Walled carbon Nanotubes (SWNTs) with controlled diameter and helicity will be synthesized by chemical vapor deposition using well-isolated catalyst nanoparticles with uniform size distributions, and these nanotubes may have potential electromechanical applications in devices. In addition, single-crystalline ferroelectric nanowires will be prepared from barium titanate and related compounds and their ferroelectric and piezoelectric properties determined by variable-temperature scanned-probe microscopy. These experiments will determine phase transitions of individual nanowires as a function of temperature and nanowire diameter. "Early College Awareness Program" will expose school students in different aspects of science, and will attract them for advanced studies in science.