Enhanced medium-range order in vapor-deposited germania glasses at elevated temperatures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34516775.
- Also identified by DOI 10.1126/sciadv.abh1117 and PMC identifier 8442899.
- Licence recorded as CC BY-NC.
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Abstract
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<sub>2</sub> 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<sub>4</sub> 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.