The Materials Machine – Daniel Gall

Date: Mon. September 30th, 2002, 12:30 pm-1:30 pm
Location: Rockefeller 221

An ongoing challenge in materials physics is to arrange atoms in a controlled manner in order to design materials with the desired physical properties. This can be achieved by developing (1) synthesis methods which control the nanometer scale arrangement of the constituent atoms and (2) tools that predict materials properties solely from their elemental composition and nanostructure. I will illustrate these two aspects of materials physics by presenting results from thin film growth of transition metal nitrides.

An atomistic understanding of growth is developed using a multiple length-scales and dimensionality approach which combines experimental and computational methods to investigate microstructural evolution of entire layers (10⁶-10¹² atoms), surface roughening and island kinetics (10²-10⁵ atoms), and single atom and molecule diffusion and reaction processes (1-10 atoms). Kinetic constraints are then used to control texture, grow single crystals, and design novel nanostructures.

Physical properties including mechanical, optical, vibrational, and electronic transport properties are determined experimentally and understood from fundamental physical concepts by means of electronic structure calculations. This understanding leads, in turn, to the controlled synthesis of novel materials including semiconductors, superconductors, ultra-hard coatings, magnetic insulators, and conducting refractory compounds.