Structural characterization and electrical properties of sintered magnesium-titanate ceramics

JOURNAL OF ALLOYS AND COMPOUNDS

卷:555

Article

Filipovic, S.¹  Obradovic, N.¹  Krstic, J.²  Scepanovic, M.³  Pavlovic, V.¹  Paunovic, V.⁴  Ristic, M. M.⁵ 

[1] Inst Tech Sci SASA, Belgrade 11000, Serbia

[2] Univ Belgrade, Inst Chem Technol & Met, Dept Catalysis & Chem Engn, Belgrade 11000, Serbia

[3] Univ Belgrade, Inst Phys, Belgrade 11080, Serbia

[4] Univ Nis, Fac Elect, Nish 18000, Serbia

[5] Serbian Acad Arts & Sci, Belgrade 11000, Serbia

关键词: Ball milling;    SEM;    Raman spectroscopy;    Sintering;    Titanates;   

DOI  :  10.1016/j.jallcom.2012.12.040

来源: Elsevier

【 摘 要 】

In this article the influence of ball miling process on structure of MgO-TiO2 system, as well as the electrical properties of samples after sintering, was investigated. The mixtures of MgO-TiO2 powders were mechanically activated in a planetary ball mill for the time period from 0 to 120 min. The influence of mechanical activation and sintering on the lattice vibrational spectra was studied by Raman spectroscopy at room temperature. Structural investigations have been performed on produced powders. Nitrogen adsorption method was used to determine the BET specific surface area and pore size distribution. Unusual results have been obtained: specific surface area continuosly decreased up to 40 min of activation and increased after that, reaching its minimun value of 5.5 m(2)/g. The Raman spectra of activated powders have shown that anatase modes have been decreasing in intensity and broadening as the time of activation extended. Also, the additional modes attributed to TiO2 II, srilankite and rutile phases started to appear as a consequence of activation. The small differences noticed in the Raman spectra of sintered samples have been explained by structural modification of MgTiO3 phase due to the presence of defects. The effects of activation and sintering process on microstructure were investigated by scanning electron microscopy (SEM). The electrical measurements showed difference in dielectric constant (epsilon(r)), loss tangent (tg delta) and specific resistance (rho) as a function of time of mechanical treatment. (C) 2012 Elsevier B. V. All rights reserved.

【 授权许可】

Free