1. National Science Foundation Goals: Understand the influence of composition and structure on the tribological (i.e., friction and wear) properties and thermal stability of diamond-like carbon nanocomposites (DLNs). Impact: Diamond-like carbon materials are in demand for use as coatings in several applications, such as advanced energy systems, manufacturing, aerospace, automotive, nanomechanical devices, and information storage sectors. Materials World Network: Mechanics and Durability of Diamond-Like Nanocomposites Robert W. Carpick, University of Pennsylvania, DMR 1107642 The methodology employed for gaining a fundamental, atomistic-scale understanding of the structure-property relationships in DLNs comprises both experiments and molecular dynamics (MD) simulations. Image courtesy of HGST

2. National Science Foundation The thermally-induced structural evolution of hydrogenated amorphous carbon films (a-C:H) was investigated in situ by X-ray photoelectron spectroscopy (XPS). A new model for the conversion of sp 3 - to sp 2 -hybridized carbon in a- C:H vs. temperature and time was developed and applied to determine the ranges of activation energies for the thermally-activated processes occurring (paper under review in APL*). Thermally-Induced Evolution of a-C:H and DLN Robert W. Carpick, University of Pennsylvania, DMR 1107642 * F. Mangolini, F. Rose, J. Hilbert, and R. W. Carpick, Applied Physics Letters, under review, 2013 In situ near-edge X-ray absorption fine structure (NEXAFS) spectroscopy heating experiments were performed at the National Synchrotron Light Source (Brookhaven National Laboratories) to investigate the structural evolution of DLN and a-C:H as a function of annealing temperature in ultra-high vacuum. The results indicated an increase in the fraction of sp 2 - bonded carbon and the clustering of the sp 2 phase upon annealing for both DLN and a-C:H.

3. National Science Foundation Molecular Dynamics (MD) Simulations Robert W. Carpick, University of Pennsylvania, DMR 1107642 Molecular dynamics (MD) simulations using the ReaxFF potential have been carried out to visualize the atomic structure of DLC and DLN. Bulk amorphous material is created by quenching liquid from 6000 K to 300 K over a few picoseconds. The atomic composition is chosen to match experiments, and the resulting structures are relaxed to the measured density. To validate the accuracy of the potential the resulting structures have been compared to experimental results from the literature, such as the variation of sp 2 /sp 3 ratio with density and the radial distribution function. These results provide evidence that the potential is well parameterized to describe these amorphous carbon systems. The MD simulations show that the structure of bulk DLN is composed of a single amorphous phase with no evidence of gaps or holes despite the low density. Structure of DLN (C – green; H – red; O – blue; Si – yellow). The structure of DLN was generated using molecular dynamics (MD) simulations (8000 atoms in a 35x35x35 Å 3 box) based on experimental composition and density

4. National Science Foundation Philly Materials Day 2013 & Clark Park Discovery Day 2013 Robert W. Carpick, University of Pennsylvania, DMR 1107642 Prof. R.W. Carpick’s Nanomechanics Laboratory took part to the “Philly Materials Day 2013” (February 2 nd, 2013) and to the “Clark Park Discovery Day 2013” (April 27 th, 2013), two day- long events aimed to raise the scientific awareness of children, teenagers, and adults about tribology and surface science. Two members of Prof. R.W. Carpick’s group explaining concepts to children and teenagers during the Philly Materials Day 2013 http://www.seas.upenn.edu/event-photo-archives/PhilMatDay_2.2.13/ The booths prepared by the Nanomechanics Laboratory comprised hands-on activities, informal science education experiences with a special focus on atomic force microscopy and carbon-based materials (diamond, graphite, and diamond-like carbon)