A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route

This work investigated the structure and dielectric behavior of precursor-derived spark plasma sintered (SPS) hafnium dioxide (HfO2). X-ray diffractograms confirmed the presence of monoclinic HfO2 (m-HfO2) and scanning electron micrographs revealed micron/nanosized grains and grain boundaries in SPS...

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Main Authors: S. S. Lokesh Vendra, Ekaterina Koroleva, Alexey Filimonov, Sergey Vakhrushev, Ravi Kumar
Format: Article
Language:English
Published: World Scientific Publishing 2025-06-01
Series:Journal of Advanced Dielectrics
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Online Access:https://www.worldscientific.com/doi/10.1142/S2010135X24500371
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author S. S. Lokesh Vendra
Ekaterina Koroleva
Alexey Filimonov
Sergey Vakhrushev
Ravi Kumar
author_facet S. S. Lokesh Vendra
Ekaterina Koroleva
Alexey Filimonov
Sergey Vakhrushev
Ravi Kumar
author_sort S. S. Lokesh Vendra
collection DOAJ
description This work investigated the structure and dielectric behavior of precursor-derived spark plasma sintered (SPS) hafnium dioxide (HfO2). X-ray diffractograms confirmed the presence of monoclinic HfO2 (m-HfO2) and scanning electron micrographs revealed micron/nanosized grains and grain boundaries in SPS m-HfO2. The theoretical density of ceramics is 94%, and the porosity is very low. In the temperature interval of 25–[Formula: see text]C, the real part of the permittivity ([Formula: see text]) is almost frequency- and temperature-independent and the [Formula: see text] value is about 21 in the frequency range 10[Formula: see text]106[Formula: see text]Hz. [Formula: see text] of SPS ceramics is higher than that of traditionally sintered HfO2 ceramics. At temperatures above 225∘C, there is a sharp increase in the permittivity and loss at low measuring frequencies. In order to comprehend the underlying conduction mechanisms, an analysis of the dispersion dependences of the dielectric response was undertaken. High permittivity values were attributed to the space charge polarization mechanism occurring at grain boundaries due to the thermally activated movement of oxygen vacancies. The DC conductivity of SPS m-HfO2 is thermally activated, and conductivity is determined by oxygen vacancies through hopping mechanism.
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institution Kabale University
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publishDate 2025-06-01
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spelling doaj-art-44ad218b20e4449f8ed2d8178077a8002025-08-20T03:51:19ZengWorld Scientific PublishingJournal of Advanced Dielectrics2010-135X2010-13682025-06-01150310.1142/S2010135X24500371A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor routeS. S. Lokesh Vendra0Ekaterina Koroleva1Alexey Filimonov2Sergey Vakhrushev3Ravi Kumar4Laboratory for High Performance Ceramics, Department of Metallurgical and Materials Engineering, Indian Institute of Technology-Madras (IIT Madras), Chennai 600036, IndiaNeutron Research Laboratory, Ioffe Institute, St. Petersburg 194021, RussiaInstitute of Electronics and Telecommunications, Peter the Great St. Petersburg Polytechnic University, St. Petersburg 195251, RussiaNeutron Research Laboratory, Ioffe Institute, St. Petersburg 194021, RussiaLaboratory for High Performance Ceramics, Department of Metallurgical and Materials Engineering, Indian Institute of Technology-Madras (IIT Madras), Chennai 600036, IndiaThis work investigated the structure and dielectric behavior of precursor-derived spark plasma sintered (SPS) hafnium dioxide (HfO2). X-ray diffractograms confirmed the presence of monoclinic HfO2 (m-HfO2) and scanning electron micrographs revealed micron/nanosized grains and grain boundaries in SPS m-HfO2. The theoretical density of ceramics is 94%, and the porosity is very low. In the temperature interval of 25–[Formula: see text]C, the real part of the permittivity ([Formula: see text]) is almost frequency- and temperature-independent and the [Formula: see text] value is about 21 in the frequency range 10[Formula: see text]106[Formula: see text]Hz. [Formula: see text] of SPS ceramics is higher than that of traditionally sintered HfO2 ceramics. At temperatures above 225∘C, there is a sharp increase in the permittivity and loss at low measuring frequencies. In order to comprehend the underlying conduction mechanisms, an analysis of the dispersion dependences of the dielectric response was undertaken. High permittivity values were attributed to the space charge polarization mechanism occurring at grain boundaries due to the thermally activated movement of oxygen vacancies. The DC conductivity of SPS m-HfO2 is thermally activated, and conductivity is determined by oxygen vacancies through hopping mechanism.https://www.worldscientific.com/doi/10.1142/S2010135X24500371Precursor ceramicsspark plasma sinteringhafnium dioxidedielectric properties
spellingShingle S. S. Lokesh Vendra
Ekaterina Koroleva
Alexey Filimonov
Sergey Vakhrushev
Ravi Kumar
A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
Journal of Advanced Dielectrics
Precursor ceramics
spark plasma sintering
hafnium dioxide
dielectric properties
title A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
title_full A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
title_fullStr A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
title_full_unstemmed A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
title_short A dielectric study on spark plasma sintered monoclinic HfO2 processed through precursor route
title_sort dielectric study on spark plasma sintered monoclinic hfo2 processed through precursor route
topic Precursor ceramics
spark plasma sintering
hafnium dioxide
dielectric properties
url https://www.worldscientific.com/doi/10.1142/S2010135X24500371
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