Next Article in Journal
Experimental Investigations on the Effect of Axial Homogenous Magnetic Fields on Propagating Vortex Flow in the Taylor–Couette System
Previous Article in Journal
Methodologies in Spectral Tuning of DSSC Chromophores through Rational Design and Chemical-Structure Engineering
Open AccessArticle

High-Temperature Dielectric Relaxation Behaviors in Mn3O4 Polycrystals

by Songwei Wang 1,2, Xin Zhang 1,2,*, Rong Yao 1, Liguo Fan 1 and Huaiying Zhou 1,2
1
School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China
2
Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China
*
Author to whom correspondence should be addressed.
Materials 2019, 12(24), 4026; https://doi.org/10.3390/ma12244026
Received: 19 October 2019 / Revised: 14 November 2019 / Accepted: 29 November 2019 / Published: 4 December 2019
(This article belongs to the Section Materials Physics)
High temperature dielectric relaxation behaviors of single phase Mn3O4 polycrystalline ceramics prepared by spark plasma sintering technology have been studied. Two dielectric relaxations were observed in the temperature range of 200 K–330 K and in the frequency range of 20 Hz–10 MHz. The lower temperature relaxation is a type of thermally activated relaxation process, which mainly results from the hopping of oxygen vacancies based on the activation energy analysis. There is another abnormal dielectric phenomenon that is different from the conventional thermally activated behavior and is related to a positive temperature coefficient of resistance (PTCR) effect in the temperature region. In line with the impedance analyses, we distinguished the contributions of grains and grain boundaries. A comparison of the frequency-dependent spectra of the imaginary impedance with imaginary electric modulus suggests that both the long range conduction and the localized conduction are responsible for the dielectric relaxations in the Mn3O4 polycrystalline samples. View Full-Text
Keywords: dielectric relaxation; activation energy; oxygen vacancies hopping; positive temperature coefficient of resistance (PTCR) effect dielectric relaxation; activation energy; oxygen vacancies hopping; positive temperature coefficient of resistance (PTCR) effect
Show Figures

Figure 1

MDPI and ACS Style

Wang, S.; Zhang, X.; Yao, R.; Fan, L.; Zhou, H. High-Temperature Dielectric Relaxation Behaviors in Mn3O4 Polycrystals. Materials 2019, 12, 4026.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop