Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug 25;14(17):4805.
doi: 10.3390/ma14174805.

Sintering Temperature, Frequency, and Temperature Dependent Dielectric Properties of Na0.5Sm0.5Cu3Ti4O12 Ceramics

Hicham Mahfoz Kotb  1   2 , Hassan A Khater  1   2 , Osama Saber  1   3 , Mohamad M Ahmad  1   4
Affiliations

Sintering Temperature, Frequency, and Temperature Dependent Dielectric Properties of Na0.5Sm0.5Cu3Ti4O12 Ceramics

Hicham Mahfoz Kotb et al. Materials (Basel). .

Abstract

NSCTO (Na0.5Sm0.5Cu3Ti4O12) ceramics have been prepared by reactive sintering solid-state reaction where the powder was prepared from the elemental oxides by mechanochemical milling followed by conventional sintering in the temperature range 1000-1100 °C. The influence of sintering temperature on the structural and dielectric properties was thoroughly studied. X-ray diffraction analysis (XRD) revealed the formation of the cubic NSCTO phase. By using the Williamson-Hall approach, the crystallite size and lattice strain were calculated. Scanning electron microscope (SEM) observations revealed that the grain size of NSCTO ceramics is slightly dependent on the sintering temperature where the average grain size increased from 1.91 ± 0.36 μm to 2.58 ± 0.89 μm with increasing sintering temperature from 1000 °C to 1100 °C. The ceramic sample sintered at 1025 °C showed the best compromise between colossal relative permittivity (ε' = 1.34 × 103) and low dielectric loss (tanδ = 0.043) values at 1.1 kHz and 300 K. The calculated activation energy for relaxation and conduction of NSCTO highlighted the important role of single and double ionized oxygen vacancies in these processes.

Keywords: dielectric properties; impedance spectroscopy; sintering.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Room temperature XRD patterns of NSCTO ceramic samples.
Figure 2
Figure 2
FE-SEM micrographs of (a) powder, (b) CS-1000, (c) CS-1025, (d) CS-1075, and (e) CS-1100 samples.
Figure 2
Figure 2
FE-SEM micrographs of (a) powder, (b) CS-1000, (c) CS-1025, (d) CS-1075, and (e) CS-1100 samples.
Figure 3
Figure 3
Temperature dependency of relative permittivity (ε′) at 10 kHz for the NSCTO ceramics.
Figure 4
Figure 4
Thermal coefficient of permittivity as a function of temperature for the NSCTO ceramics.
Figure 5
Figure 5
Frequency dependence of (a) ε′, (b) tanδ at 300 K for NSCTO ceramics, and (c) the frequency dependence of ε′ and tanδ at selected temperatures for CS-1025.
Figure 6
Figure 6
(a) The variation of the fitting parameter α with temperature, and (b) the Arrhenius plot for relaxation time for the NSCTO ceramic samples.
Figure 7
Figure 7
(a) Room temperature impedance complex plane plots for the NSCTO and (b) zoom-in for the high frequency region.
Figure 8
Figure 8
(a) Frequency dependency of σac at 400 K for NSCTO samples and (b) frequency dependency of σac at selected temperatures for CS-1075 NSCTO sample.
Figure 9
Figure 9
The Arrhenius plots of dc conductivity for CS-1000, CS-1025, CS-1075, and CS-1100 NSCTO samples.
Figure 10
Figure 10
Spectra of Z″ at selected temperatures for (a) CS-1000, (b) CS-1025, (c) CS-1075, and (d) CS-1100. The inset of each figure depicts the Arrhenius plot for the relaxation time.
See this image and copyright information in PMC

References

    1. Wang Y., Jie W., Yang C., Wei X., Hao J. Colossal permittivity materials as superior dielectrics for diverse applications. Adv. Funct. Mater. 2019;29:1808118. doi: 10.1002/adfm.201808118. - DOI
    1. Ramireza A.P., Subramanian M.A., Gardel M., Blumberg G., Lib D., Vogt T., Shapiro S.M. Giant dielectric constant response in a copper-titanate. J. Solid State Commun. 2000;115:217–220. doi: 10.1016/S0038-1098(00)00182-4. - DOI
    1. Subramanian M.A., Li D., Duan N., Reisner B.A., Sleight A.W. High dielectric constant in ACu3Ti4O12 and ACu3Ti3FeO12 phases. Solid State Chem. 2000;151:323–325. doi: 10.1006/jssc.2000.8703. - DOI
    1. Riquet G., Marinel S., Breard Y., Harnois C., Pautrat A. Direct and hybrid microwave solid state synthesis of CaCu3Ti4O12 ceramic: Microstructures and dielectric properties. Ceram. Int. 2018;44:15228–15235. doi: 10.1016/j.ceramint.2018.05.164. - DOI
    1. Jesus L.M., Santos J.C.A., Sampaio D.V., Barbosa L.B., Silva R.S., M’Peko J.C. Polymeric synthesis and conventional versus laser sintering of CaCu3Ti4O12 electroceramics: (micro)structures, phase development and dielectric properties. J. Alloys Compd. 2016;654:482–490. doi: 10.1016/j.jallcom.2015.09.027. - DOI

LinkOut - more resources