skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite

Abstract

(1-x)CaCu{sub 3}Ti{sub 4}O{sub 12} + (x)Al{sub 2}O{sub 3} composite (0 ≤ x ≤0.25) was prepared via conventional solid-state reaction method. The fabrication of sample was started with synthesizing stoichiometric CCTO from CaCO{sub 3}, CuO and TiO{sub 2} powders, then wet-mixed in deionized water for 24 h. The process was continued with calcined CCTO powder at 900 °C for 12 h before sintered at 1040 °C for 10 h. Next, the calcined CCTO powder with different amount of Al{sub 2}O{sub 3} were mixed for 24 h, then palletized and sintered at 1040 °C for 10. X-ray diffraction analysis on the sintered samples showed that CCTO powder was in a single phase, meanwhile the trace of secondary peaks which belong to CaAl{sub 2}O{sub 4} and Corundum (Al{sub 2}O{sub 3}) could be observed in the other samples Scanning electron microscopy analysis showed that the grain size of the sample is firstly increased with addition of Al{sub 2}O{sub 3} (x = 0.01), then become smaller with the x > 0.01. Microwave dielectric properties showed that the addition of Al{sub 2}O{sub 3} (x = 0.01) was remarkably reduced the dielectric loss while slightly increased the dielectric permittivity. However, further addition of Al{sub 2}O{sub 3} wasmore » reduced both dielectric loss and permittivity at least for an order of magnitude.« less

Authors:
; ; ;  [1]; ;  [2];  [3]
  1. School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)
  2. Advance Materials Research Cluster, Faculty of Earth Sciences, Universiti Malaysia Kelantan, Jeli Campus, 17600 Jeli, Kelantan (Malaysia)
  3. School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)
Publication Date:
OSTI Identifier:
22608472
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1756; Journal Issue: 1; Conference: ICoFM 2016: 2. international conference on functional materials and metallurgy, Penang (Malaysia), 28 May 2016; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; CALCIUM CARBONATES; CALCIUM COMPOUNDS; COMPOSITE MATERIALS; COPPER COMPOUNDS; COPPER OXIDES; CORUNDUM; DIELECTRIC MATERIALS; FABRICATION; GRAIN SIZE; MICROWAVE RADIATION; PERMITTIVITY; POWDERS; SCANNING ELECTRON MICROSCOPY; SOLIDS; STOICHIOMETRY; TITANATES; TITANIUM OXIDES; X-RAY DIFFRACTION

Citation Formats

Rahman, Mohd Fariz Ab, Abu, Mohamad Johari, Zaman, Rosyaini Afindi, Ahmad, Zainal Arifin, Karim, Saniah Ab, Mohamed, Julie Juliewatty, E-mail: juliewatty.m@umk.edu.my, and Ain, Mohd Fadzil. Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite. United States: N. p., 2016. Web. doi:10.1063/1.4958750.
Rahman, Mohd Fariz Ab, Abu, Mohamad Johari, Zaman, Rosyaini Afindi, Ahmad, Zainal Arifin, Karim, Saniah Ab, Mohamed, Julie Juliewatty, E-mail: juliewatty.m@umk.edu.my, & Ain, Mohd Fadzil. Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite. United States. doi:10.1063/1.4958750.
Rahman, Mohd Fariz Ab, Abu, Mohamad Johari, Zaman, Rosyaini Afindi, Ahmad, Zainal Arifin, Karim, Saniah Ab, Mohamed, Julie Juliewatty, E-mail: juliewatty.m@umk.edu.my, and Ain, Mohd Fadzil. 2016. "Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite". United States. doi:10.1063/1.4958750.
@article{osti_22608472,
title = {Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite},
author = {Rahman, Mohd Fariz Ab and Abu, Mohamad Johari and Zaman, Rosyaini Afindi and Ahmad, Zainal Arifin and Karim, Saniah Ab and Mohamed, Julie Juliewatty, E-mail: juliewatty.m@umk.edu.my and Ain, Mohd Fadzil},
abstractNote = {(1-x)CaCu{sub 3}Ti{sub 4}O{sub 12} + (x)Al{sub 2}O{sub 3} composite (0 ≤ x ≤0.25) was prepared via conventional solid-state reaction method. The fabrication of sample was started with synthesizing stoichiometric CCTO from CaCO{sub 3}, CuO and TiO{sub 2} powders, then wet-mixed in deionized water for 24 h. The process was continued with calcined CCTO powder at 900 °C for 12 h before sintered at 1040 °C for 10 h. Next, the calcined CCTO powder with different amount of Al{sub 2}O{sub 3} were mixed for 24 h, then palletized and sintered at 1040 °C for 10. X-ray diffraction analysis on the sintered samples showed that CCTO powder was in a single phase, meanwhile the trace of secondary peaks which belong to CaAl{sub 2}O{sub 4} and Corundum (Al{sub 2}O{sub 3}) could be observed in the other samples Scanning electron microscopy analysis showed that the grain size of the sample is firstly increased with addition of Al{sub 2}O{sub 3} (x = 0.01), then become smaller with the x > 0.01. Microwave dielectric properties showed that the addition of Al{sub 2}O{sub 3} (x = 0.01) was remarkably reduced the dielectric loss while slightly increased the dielectric permittivity. However, further addition of Al{sub 2}O{sub 3} was reduced both dielectric loss and permittivity at least for an order of magnitude.},
doi = {10.1063/1.4958750},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1756,
place = {United States},
year = 2016,
month = 7
}
  • In this present work, CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) was synthesized by conventional solid-state reaction technique. The synthesis process was carried out in two phases; by conventional process (calcination and sintering at 1080°C for 10 hours) and phase II involves the micro assisted pre sintering of conventionally calcined CCTO for very short soaking time of 30 min at 1080°C in a microwave furnace followed by sintering at 1080°C for 10 hours in conventional furnace. X-ray diffraction (XRD) patterns confirmed the formation of single phase ceramic. Dielectric properties were studied over the frequency range from 50Hz -5MHz at temperatures (273K-343K). It wasmore » observed that pre- microwave sintering enhance the dielectric constant values from 10900 to 11893 and respectively reduces the dielectric loss values from 0.49 to 0.34 at room temperature(1 KHz). CCTO ceramics which are found desirable for many technological applications. The effect is more pronounced at low frequencies of applied electric field.« less
  • Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3}-Mg{sub 2}TiO{sub 4} composite ceramics are fabricated via the conventional solid-state reaction method. The microstructures, dielectric tunability, and microwave properties of composite ceramics are investigated. The dielectric constant is tailored from 335 to 35 by manipulating the addition of Mg{sub 2}TiO{sub 4} from 50% to 80% weight ratio and the tunability is 10.8% measured at 10 kHz for the 80% Mg{sub 2}TiO{sub 4} addition. The composite ceramics with high Q value (>200) at L band are useful for potential tunable microwave device applications in the wireless communication system.
  • Crack-free, dense, and uniform Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3}(BST)-Bi{sub 1.5}Zn{sub 1.0}Nb{sub 1.5}O{sub 7}(BZN) composite thin films were deposited on (100) LaAlO{sub 3} (100) SrTiO{sub 3}, and (100) MgO substrates via a pulsed laser deposition, using a combined target of BST and BZN ceramics. Phase composition and microstructure of the BST-BZN thin films were characterized by x-ray diffraction and scanning electron microscopy. The films, on LAO, STO, and MgO substrates, showed zero-field microwave ({approx}7.7 GHz) dielectric constants of 471, 435, and 401, dielectric loss tangents of 0.0048, 0.0043, and 0.0037, and dielectric tunabilities of 6.2%, 6.0%, and 5.7% at {approx}8.1 kV/cm, respectively.more » The good physical and electrical properties of the BST-BZN composite thin films make them promising candidates for microwave device applications.« less
  • Highlights: • Microwave properties of ϵ{sub r} ∼ 16.3, Q × f ∼ 50,084 GHz and τ{sub f} ∼ 1.5 ppm/°C are achieved. • The τ{sub f} value of the LMZN ceramic can be adjusted to near zero by adding BV. • The LMZN–BV composite ceramic can be well sintered at a relatively low temperature. • The composite ceramic has a good chemical compatibility with Ag electrode. - Abstract: In this work, the (1 − x)Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6}–xBa{sub 3}(VO{sub 4}){sub 2} (x = 0.1–0.35) ceramics were prepared via a conventional solid state reaction route. The phase composition,more » microstructure and microwave dielectric properties were investigated by an X-ray diffractometer (XRD), a scanning electron microscope and a network analyzer. The XRD results indicated that the Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6} and Ba{sub 3}(VO{sub 4}){sub 2} phases could well coexist without forming any secondary phases. The dielectric constant (ϵ{sub r}) and quality factor (Q × f) values of the Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6} ceramic decreased with the addition of Ba{sub 3}(VO{sub 4}){sub 2} phase, however its temperature coefficient of resonant frequency (τ{sub f}) value was improved significantly. Excellent microwave dielectric properties of ϵ{sub r} ∼ 16.3, Q × f ∼ 50,084 GHz (at 8.64 GHz) and τ{sub f} ∼ 1.5 ppm/°C were achieved for the x = 0.3 sample when sintered at 950 °C for 4 h. The chemical compatibility with Ag electrode indicated that the 0.7Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6}–0.3Ba{sub 3}(VO{sub 4}){sub 2} composite ceramic would be a promising material for the low temperature cofired ceramic applications.« less
  • Highlights: • High ϵ′ PVDF/CCTO and La doped CCTO composites prepared by Extrusion. • With addition of ceramic, there is substantial increase in the ϵ′ of matrix PVDF. • Composites exhibit double relaxation behavior. - Abstract: Melt extrusion process has been used to prepare high relative permittivity, ϵ' PVDF–CCTO and PVDF–LaCCTO composites. Phase composition has been studied using powder X-ray diffraction (XRD). Microstructural, dielectric and mechanical properties have also been studied. Young's modulus of PVDF increases with the ceramic reinforcement. Dielectric measurements are made in the frequency range 10{sup −2}–10{sup 6} Hz using two probe Novocontrol impedance analyser (ZG4) frommore » room temp to 120 °C to study the dielectric relaxation. There is a substantial increase in ϵ' of the matrix PVDF on addition of LaCCTO.« less