Negative capacitance of nanocomposites with CoFeZr nanoparticles embedded into silica matrix
Artykuł w czasopiśmie
MNiSW
100
Lista 2021
| Status: | |
| Autorzy: | Fedotova Julia A., Pashkevich Alexei V., Ronassi Ali Arash, Kołtunowicz Tomasz, Fedotov Aleksander K., Żukowski Paweł, Fedotov Aleksander S., Kasiuk Julia V., Kalinin Yury, Sitnikov Anton V., Fedotova Vera V., Evtuh A. |
| Dyscypliny: | |
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| Rok wydania: | 2020 |
| Wersja dokumentu: | Drukowana | Elektroniczna |
| Język: | angielski |
| Wolumen/Tom: | 511 |
| Numer artykułu: | 166963 |
| Strony: | 1 - 7 |
| Web of Science® Times Cited: | 7 |
| Scopus® Cytowania: | 7 |
| Bazy: | Web of Science | Scopus |
| Efekt badań statutowych | NIE |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | TAK |
| Licencja: | |
| Sposób udostępnienia: | Witryna wydawcy |
| Wersja tekstu: | Ostateczna wersja opublikowana |
| Czas opublikowania: | W momencie opublikowania |
| Data opublikowania w OA: | 4 maja 2020 |
| Abstrakty: | angielski |
| The study presents frequency dependences of real part of admittanceZ′(f) and phase shift angleθ(T,f)innanogranularfilms containing CoFeZr nanoparticles with“core-shell”structure embedded into SiO2matrix. The3μm thicknesses (Co41Fe49Zr10)x(SiO2)100−xfilms with 20≤x≤80 at.% were deposited in vacuum chamberevacuated either with pure Ar (Set 1 samples) or Ar + O2gas mixture (Set 2) using ion-beam sputteringtechnique. After characterization by X-Ray diffraction, Mössbauer spectroscopy, scanning electron microscopyand magnetization studies, thefilms both of Set 1 and Set 2 samples were subjected by admittance measurementsat 300 K in the frequency range of 0.1–1000 kHz. Mössbauer spectroscopy have shown that oxidized CoFeZrnanoparticles in Set 2 samples contain semiconducting iron-based oxides with Fe3+charge states of iron ions.The observedZ′(f) andθ(f) dependencies for the Set 2films below thexchave shown dielectric regime of carriertransport. They also exhibited that at weak AC electricfields inductive-like contribution to reactive part ofadmittance (with positiveθvalues) prevails over the capacitive onef> 10 kHz. This effect of the so-called“negative capacitance”was explained by the delay of current, formed by electrons hopping between nano-particles, relative to applied bias voltage. This delay is forced by formation of dipoles of charged FeCoZr na-noparticles with native Fe-based oxide“shells”around them that results in the increase of mean life time ofhopping electrons on nanoparticles with“core-shell”structure. |
