Origin of giant dielectric constant and conductivity behavior in Zn{sub 1−x}Mg{sub x}O (0 ≤ x ≤ 0.1) ceramics

Journal Article · Mon Feb 15 00:00:00 EST 2016 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.10.006· OSTI ID:22584282

Paramesh, G. ^[1]; Prakash, B. Shri ^[2]; Meher, K. R.S. Preethi ^[1]; Varma, K. B.R., ^[1]

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1. Materials Research Center, Indian Institute of Science, Bangalore 560 012 (India)
2. Surface Engineering Division, Council of Scientific and Industrial Research-National Aerospace Laboratories, Bangalore 560 017 (India)

Highlights: • Mg doped zinc oxide ceramics were fabricated by co-precipitation/solid state reaction. • MZO ceramics shown a Debye type and colossal dielectric response. • Physical absorption of atmospheric water vapor contributes these high permittivity. • The fabricated ceramic shows Maxwell–Wagner type of relaxation. - Abstract: Zn{sub 1−x}Mg{sub x}O ( ≤ x ≤ 0.1) ceramics were fabricated by conventional solid-state reaction of co-precipitated zinc oxide and magnesium hydroxide nanoparticles. Structural and morphological properties of the fabricated ceramics were studied using X-ray diffraction and scanning electron microscopic analysis. The dielectric measurements of the ceramics were carried out as a function of frequency and temperature respectively. Interestingly, Mg doped ZnO (MZO) samples exhibited colossal dielectric response (∼1 × 10{sup 4} at 1 kHz) with Debye like relaxation. The detailed dielectric studies and thermal analyses showed that the unusual dielectric response of the samples were originated from the defected grain and grain boundary (GB) conductivity relaxations due to the absorbed atmospheric water vapor (moisture). Impedance spectroscopy was employed to determine the defected grain and GB resistances, capacitances and which supported Maxwell–Wagner type relaxation phenomena.

• OSTI ID: 22584282
• Journal Information: Materials Research Bulletin, Vol. 74; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
CAPACITANCE
CERAMICS
COPRECIPITATION
DIELECTRIC MATERIALS
DOPED MATERIALS
FREQUENCY DEPENDENCE
GRAIN BOUNDARIES
IMPEDANCE
KHZ RANGE
MAGNESIUM HYDROXIDES
NANOPARTICLES
PERMITTIVITY
RELAXATION LOSSES
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
WATER VAPOR
X-RAY DIFFRACTION
ZINC OXIDES