Abstract
Abstract
The mechanical loss of amorphous thin films of germania (GeO2) and titania-doped germania (Ti:GeO2) deposited by ion-beam sputtering onto silicon double-paddle oscillators was studied from 10 K to 290 K. Undoped germania was found to show a wide cryogenic mechanical loss peak centered at
∼
60
K with
ϕ
=
3.1
×
10
−
3
, which decreases to
1.1
×
10
−
3
as Ti-concentration increases to 44%. In addition to decreasing the height of this low-temperature peak, Ti-doping increases its width, and shifts its position toward lower temperatures. Annealing reduces the room temperature mechanical loss of Ti:GeO2 and increases its cryogenic mechanical loss, which is consistent with trends observed in most amorphous oxides.
Funder
Division of Electrical, Communications and Cyber Systems
Gordon and Betty Moore Foundation
Science and Technology Facilities Council
Division of Physics
Subject
Physics and Astronomy (miscellaneous)