Effect of processing routes on microstructure, electrical and dielectric behavior of Mg-doped CaCu3Ti4O12 electro-ceramic

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2013-09, Vol.112 (4), p.891-900
• Main Authors: Singh, Laxman, Rai, U. S., Mandal, K. D., Rai, Alok Kumar
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Dielectric loss and relaxation; Dielectric properties of solids and liquids; Dielectric relaxation; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Dispersions; Exact sciences and technology; Grain boundaries; Machines; Manufacturing; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotechnology; Optical and Electronic Materials; Permittivity (dielectric function); Physics; Physics and Astronomy; Processes; Scanning electron microscopy; Surfaces and Interfaces; Thin Films; Titanates; Transmission electron microscopy
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-012-7443-z

In the present communication, data on magnesium-doped calcium copper titanate CaCu 2.90 Mg 0.10 Ti 4 O 12 (CCMTO) electro-ceramic, synthesized by the semi-wet route (SWR), ball-milled route (BMR) and solid-state route (SSR), is characterized by TG-DTA, XRD, SEM, EDX and TEM techniques. XRD confirmed the formation of single phase in CCMTO ceramic. The CuO phase present at grain boundaries in SWR ceramic was shown by the SEM micrograph, which was verified by EDX. The TEM image of SWR ceramic shows nanocrystalline particles in the range 80±20 nm. The value of the dielectric constant of SWR ( ε r ∼20091) ceramic is higher than those of BMR and SSR ( ε r ∼1247) ceramics at 1 kHz at 450 K. A dielectric relaxation has been observed in the frequency range 100 Hz–100 kHz. The high-temperature dielectric dispersion shows one large low-frequency response and two Debye-type relaxations. The impedance and modulus studies show the highest grain-boundary resistance for BMR ceramic.