English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

A potassium-ion electret, which is a key element of vibration-poweredmicroelectromechanical generators, can store negative charge almostpermanently. However, the mechanism by which this negative charge is stored isstill unclear. We theoretically study the atomic and electronic structures ofamorphous silica (a-SiO2) with and without potassium atoms usingfirst-principles molecular-dynamics calculations. Our calculations show that afivefold-coordinated Si atom with five Si-O bonds (an SiO5 structure) is thecharacteristic local structure of a-SiO2 with potassium atomsm, which becomesnegatively charged and remains so even after removal of the potassium atoms.These results indicate that this SiO5 structure is the physical origin of therobust negative charge observed in potassium-ion electrets. We also find thatthe SiO5 structure has a Raman peak at 1000cm-1.

applied physics letters

Negative-charge-storing mechanism of potassium-ion electrets used for  vibration-powered generators: Microscopic study of a-SiO2 with and without  potassium atoms