Investigation of microstructure and dielectric behavior of Bi2/3Cu3−xMgxTi4O12 (x = 0, 0.05, 0.1 and 0.2) ceramics synthesized by semi-wet route

Vishnu Shankar Rai,Vinod Kumar,Dinesh Prajapati,K D Mandal,Manish Kumar Verma,Santosh Pandey,Atendra Kumar,Shruti Singh

doi:10.1007/s10854-021-05483-8

Vishnu Shankar Rai, Vinod Kumar + Show 6 more

Open Access

https://doi.org/10.1007/s10854-021-05483-8

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Abstract

In this manuscript, we have reported the synthesis and characterization of Mg-doped and undoped BCTO ceramic (Bi2/3Cu3−xMgxTi4O12, x = 0, 0.05, 0.1 and 0.2) sintered at 1173 K for 8 h, which have been prepared by the semi-wet route. The single-phase formation of ceramic was approved by the XRD pattern. The microstructural properties were studied by TEM and AFM. The samples were characterized by dielectric and impedance spectroscopic properties. The dielectric constant (er) was calculated to be 3024 for BCTO ceramics at 423 K and 100 Hz. The tangent loss (tan δ) value was calculated to be 0.45 for BCTO ceramic at 423 K and 10 kHz. The internal Barrier Layer Capacitance (IBLC) mechanism was responsible for the high value of the dielectric constant. XPS spectroscopy confirmed the oxidation state of the elements present in the ceramic. It was observed from Impedance and modulus studies that there was the existence of the Maxwell–Wagner form of relaxation in the ceramics. In the temperature range 300–500 K, the Bi2/3Cu3−xMgxTi4O12 (where x = 0, 0.05, 0.1, 0.2) ceramic follows Arrhenius behavior with an almost single slope.

Highlights

ACu3Ti4O12 type of perovskite oxide was the first time revealed in 1967 [1], which was able to produce high dielectric constant
Cation non-stochiometry mechanism relating to a Cu deficiency in the interior grain area was alleged to responsible for this effect [22,23,24].In this present study, We have reported the effects of Mg doping on Cu sites on dielectric properties and Impedance studies of BCTO Ceramic, which was synthesized through the semi-wet method
X-ray diffraction pattern of Mg doped and undoped BCTO ceramics Bi2/3Cu3-xMgxTi4O12(where x=0, 0.05,0.1,0.2) sintered at 1173 K for 8 h is presented in figure 1, which clearly shows BCTO phase(JCPDS card no. 46-0725).The main XRD diffraction peaks of BCTO ceramic corresponding to (2 1 1),(2 2 0),(3 1 0),(2 2 2),(3 2 1), (4 0 0), (4 2 2), (4 4 0) planes were found to have the same as CCTO (JCPDS card no. 75-2188)

Summary

1.Introduction

ACu3Ti4O12 (where A =Ca, Y2/3, Bi2/3, Gd2/3) type of perovskite oxide was the first time revealed in 1967 [1], which was able to produce high dielectric constant. The search for ultrahigh permittivity (εr> 103) materials is one of the most popular research topics in the fields of microelectronics and energy storage devices.CaCu3Ti4O12(CCTO), a typical ACu3Ti4O12 (ACTO, where A = Ca, Cd, La2/3, Y2/3, Bi2/3, Na1/2La1/2, Na1/2Y1/2, or Na1/2Bi1/2, Sr) ceramic, has been widely studied due to its ultrahigh dielectric permittivity and good frequency/thermal stability. Bi2/3Cu3Ti4O12(BCTO) is isostructural with CCTO, has been reported in the literature It indicated the temperature and frequency dependence of dielectric as CCTO [14,15,16]. The sources of high permittivity in ACTO materials would include extrinsic processes According to this reasoning, an IBLC model, i.e. semi-conducting grains separated by isolating grain boundaries, is currently the most accepted way to explain this phenomenon [19,20,21].

Material Synthesis

4.Results and discussion

Microstructural Studies

Impedance spectroscopic studies

Conclusion