Investigating the potential of Zn2+, Cd2+ and Ni2+ substituted bismuth magnesium tantalate pyrochlores as a new class of ceramic dielectrics

被引：0

作者：

Khaw, C. C. ^{[1
]}

Tan, P. Y. ^{[2
]}

Tan, K. B. ^{[2
]}

Chan, K. Y. ^{[3
]}

Murthy, H. C. Ananda ^{[4
]}

Balachandran, R. ^{[5
]}

Chen, S. K. ^{[6
]}

Kechik, M. M. A. ^{[6
]}

Lee, O. J. ^{[7
]}

Lu, M. ^{[8
]}

机构：

[1] Univ Tunku Abdul Rahman, Lee Kong Chian Fac Engn & Sci, Dept Mech & Mat Engn, Kajang 43000, Selangor, Malaysia

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

[3] Multimedia Univ, Fac Engn, Ctr Adv Devices & Syst, Cyberjaya 63100, Selangor, Malaysia

[4] Saveetha Univ, Saveetha Inst Med & Tech Sci SIMATS, Saveetha Dent Coll & Hodp, Dept Prosthodont, Chennai 600077, Tamil Nadu, India

[5] Adama Sci & Technol Univ, Dept Elect & Commun Engn, POB 1888, Adama, Ethiopia

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

[7] Univ Malaysia Terengganu, Fac Sci & Marine Environm, Kuala Nerus 21030, Terengganu, Malaysia

[8] Jilin Normal Univ, Key Lab Funct Mat Phys & Chem, Joint Lab MXene Mat, Minist Educ, Changchun 130103, Jilin, Peoples R China

来源：

JOURNAL OF THE INDIAN CHEMICAL SOCIETY | 2025年 / 102卷 / 04期

关键词：

Tantalates; Pyrochlores; Dielectric properties; Ceramic capacitor; ELECTRICAL-PROPERTIES;

D O I：

10.1016/j.jics.2025.101637

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

This study examined the impact of zinc (Zn), cadmium (Cd) and nickel (Ni) transition metals on the formation, structure and dielectric properties of bismuth magnesium tantalate (BMT) pyrochlores. A one-to-one substitution of Mg2+ with Zn2+, Cd2+ and Ni2+ in BMT pyrochlore was proposed, with Zn2+ (0.74 & Aring;) and Ni2+ (0.69 & Aring;) substituting the 6-coordinated B-site Mg2+ (0.72 & Aring;), while Cd2+ (1.10 & Aring;), possessing a similar ionic radius to Bi3+ (1.17 & Aring;), replaced Mg2+ (0.90 & Aring;) at the 8-coordinated A-site. The resulting doped BMT pyrochlore solid solutions adhered to the formulas: (Bi-3.Mg-5(0).(5))(Mg-1.3-xZnxTa2.(7))O-13.(8) (0 <= x <= 0.6), (Bi-3.Mg-5(0).(5))(Mg-1.3-xNixTa2.(7))O-13.(8) (0 <= x <= 0.1) and (Bi-3.Mg-5(0).Cd-5-x(x))(Mg-1.Ta-3(2).(7))O-13.(8) (0 <= x <= 0.1). X-ray diffraction (XRD) confirmed their phase purity, with lattice parameters ranging from 10.5515 (10) to 10.6312 (21) & Aring;. Notably, grain size remained consistent (1.3-22.4 mu m) across these modified BMT pyrochlores, exhibiting relative densities >= 90 % of the theoretical value. Scherrer and Williamson-Hall analyses indicated crystallite sizes within the 31-68 nm range. Furthermore, thermal stability was confirmed over similar to 30-1000 degrees C due to the absence of thermal events. The Ni-doped BMT pyrochlore (x = 0.1) demonstrated enhanced conductivity (activation energy, E-a = 1.38 eV) compared to the undoped material (E-a = 1.47 eV). Conversely, Zn- and Cd-doped BMT pyrochlores showed reduced conductivity (E-a approximate to 1.53 eV and 1.51 eV, respectively) with increasing dopant concentration. Specifically, Zn-doped (x = 0.6) and Cd-doped (x = 0.1) BMT exhibited favourable dielectric properties: moderately high dielectric constants (epsilon ' approximate to 80), low dielectric loss (tan delta approximate to 2 x 10(-3)) and a low temperature coefficient of dielectric constant (TC epsilon' approximate to -200 to -240 ppm/degrees C), making them suitable for ceramic capacitor applications.

引用

页数：8