Investigation of the phase formation and dielectric properties of Bi7Ta3O18

JOURNAL OF ALLOYS AND COMPOUNDS

卷:590

Article

Chon, M. P.¹  Tan, K. B.¹  Khaw, C. C.²  Zainal, Z.¹  Yap, Y. H. Taufiq¹  Chen, S. K.³  Tan, P. Y.¹ 

[1] Univ Putra Malaysia, Dept Chem, Fac Sci, Serdang 43400, Selangor, Malaysia

[2] Univ Tunku Abdul Rahman, Dept Mech & Mat Engn, Fac Sci & Engn, Kuala Lumpur 53300, Malaysia

[3] Univ Putra Malaysia, Dept Phys, Fac Sci, Serdang 43400, Selangor, Malaysia

关键词: Ceramics;    Sintering;    Powder diffraction;    Dielectric properties;   

DOI  :  10.1016/j.jallcom.2013.11.028

来源: Elsevier

【 摘 要 】

Polycrystalline Bi7Ta3O18 was synthesised at the firing temperature of 950 degrees C over 18 h via conventional solid state method. It crystallised in a monoclinic system with space group C2/m, Z = 4 similar to that reported diffraction pattern in the Inorganic Crystal Structure Database (ICSD), 1-89-6647. The refined lattice parameters were a = 34.060 (3) angstrom, b = 7.618 (9) angstrom, c = 6.647 (6) angstrom with alpha = gamma = 90 degrees and beta = 109.210 (7), respectively. The intermediate phase was predominantly in high-symmetry cubic structure below 800 degrees C and finally evolved into a low-symmetry monoclinic structured, Bi7Ta3O18 at 950 degrees C. The sample contained grains of various shapes with different orientations in the size ranging from 0.33-22.70 mu m. The elemental analysis showed the sample had correct stoichiometry with negligible Bi2O3 loss. Bi7Ta3O18 was thermally stable and it exhibited a relatively high relative permittivity, 241 and low dielectric loss, 0.004 at room temperature, similar to 30 degrees C and frequency of 1 MHz. (C) 2014 Published by Elsevier B.V.

【 授权许可】

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