DIRECT ATOMISTIC SIMULATION OF QUARTZ-CRYSTAL OSCILLATORS - BULK PROPERTIES AND NANOSCALE DEVICES

Current experimental research aims to reduce the size of quartz crysta l oscillators into the submicrometer range. Devices then comprise mult imillion atoms and operating frequencies will be in the gigahertz regi me. Such characteristics make direct atomic scale simulation feasible using large scale parallel computing. Here, we describe molecular-dyna mics simulations on bulk and nanoscale device systems focusing on elas tic constants and flexural frequencies. Here we find (a) in order to a chieve elastic constants within 1% of those of the bulk requires appro ximately one million atoms; precisely the experimental regime of inter est; (b);differences from continuum mechanical frequency predictions a re observable for 17 nm devices; (c) devices with 1% defects exhibit d ramatic anharmonicity. A subsequent paper describes the direct atomist ic simulation of operating characteristics of a micrometer scale devic e. A PAPS cosubmission gives algorithmic details.