Electrical/dielectric properties of metal-oxide nanofilms via anodizing Al/Hf metal layers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F18%3APU130663" target="_blank" >RIV/00216305:26620/18:PU130663 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Electrical/dielectric properties of metal-oxide nanofilms via anodizing Al/Hf metal layers

Original language description

Hafnium oxide (HfO2) is a high-temperature ceramic with excellent electrical, dielectric and optical properties, which may be substantially enhanced in the nanostructured material. Here, we have developed selforganized arrays of hafnium-oxide nanorods and examined their properties by electrochemical impedance spectroscopy (EIS). For sample preparation, Al/Hf layers are magnetron sputtered onto SiO2/Si substrates, anodized and then re-anodized to a more anodic potential. This results in the growth of a porous alumina film, followed by pore-assisted oxidation of the Hf underlayer. The films consist of discrete HfOx protrusions, penetrating the alumina pores and anchored to a uniform oxide layer that forms under the pores. Postanodizing treatments include annealing at 600°C in air or vacuum and selective dissolution of the alumina overlayer. The electrical/dielectric behavior of the hafnium oxide nanorod arrays, embedded in or free from alumina, was EIS-investigated in a borate buffer solution. In the re-anodized (not annealed) state the bottom oxide layer behaves as a good dielectric whereas the nanorods are semiconducting in nature. This situation does not change substantially by the annealing in air, still resulting in a dielectric bottom layer and semiconducting nanorods. However, after the annealing in vacuum, the whole film becomes an n-type semiconductor. Further investigation is in progress to understand the formation-structure-morphology relationship, aiming at exploring the functional properties of the films.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Project

<a href="/en/project/GA17-13732S" target="_blank" >GA17-13732S: Multifunctional nanoarrays of HfO2- and ZrO2-based electroceramics highly aligned on substrates (ZiHaN)</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Conference Proceedings of 9th International Conference on Nanomaterials - Research & Application (Nanocon 2017)

ISBN

978-80-87294-81-9

ISSN

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e-ISSN

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Number of pages

6

Pages from-to

51-56

Publisher name

TANGER Ltd.

Place of publication

Ostrava, Czech Republic

Event location

Brno

Event date

Oct 18, 2017

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000452823300007