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Glasses are nonequilibrium solids with properties highly dependent on their method of preparation. In vapor-deposited molecular glasses, structural organization could be readily tuned with deposition rate and substrate temperature. Here, we show that the atomic arrangement of strong network-forming GeO 2 glass is modified at medium range (<2 nm) through vapor deposition at elevated temperatures. Raman spectral signatures distinctively show that the population of six-membered GeO 4 rings increases at elevated substrate temperatures. Deposition near the glass transition temperature is more efficient than postgrowth annealing in modifying atomic structure at medium range. The enhanced medium-range organization correlates with reduction of the room temperature internal friction. Identifying the microscopic origin of room temperature internal friction in amorphous oxides is paramount to design the next-generation interference coatings for mirrors of the end test masses of gravitational wave interferometers, in which the room temperature internal friction is a main source of noise limiting their sensitivity. 

The effects of annealing on the atomic structures of , , and are investigated using accelerated molecular dynamics (MD) simulations. Using population annealing with Boltzmann resampling to expedite the MD simulations, it is shown that annealed models demonstrate subtle but statistically significant changes in the structure. Consistent with experiments, the simulations show that effects of annealing on the atomic structures of these amorphous oxides are more pronounced in the medium‐range order than in the short‐range order.