Influence of Mn doping on electrical conductivity of lead free BaZrTiO3 perovskite ceramic
Influence of Mn doping on electrical conductivity of lead free BaZrTiO3 perovskite ceramic
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DOI：
10.1016/j.ceramint.2018.03.039
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发表时间：
2018-06
影响因子：
5.2
通讯作者：
Kanta Maan Sangwan;N. Ahlawat;S.Usha Rani;S. Rani;R. Kundu
中科院分区：
文献类型：
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作者：
Kanta Maan Sangwan;N. Ahlawat;S.Usha Rani;S. Rani;R. Kundu
采用固相反应法制备了x = 分别为0.0 0、0.0 1、0.0 2和0.0 3的掺锰钛酸钡无铅陶瓷。用Rietveld精修后的X射线衍射图证实了单相的四方结构。扫描电子显微镜(SEM)显示，无规则取向的颗粒分布不均匀，并有一些空洞。利用阻抗分析仪研究了掺锰BZT陶瓷在493K-673K温度范围内宽频段的电导率。无锰化合物的电导率色散行为服从Jonscher二次幂定律，而掺锰化合物的电导率色散行为服从一次幂定律。各种参数，即。通过对实验数据的理论拟合，估算了直流电导率(σDC)、指前因子(A)、频率指数(S)和激活能(Ea)。直流电导率的倒数与温度的关系符合阿累尼乌斯定律，说明了热激活的传导机制。得到的活化能(EA)值表明，导电机制是由氧空位和氧离子的迁移引起的。所有样品都表现出负的电阻温度系数(NTCR)，因此表现出半导体行为。这种环保型无铅陶瓷可以开发设计先进的材料，适用于燃料电池电解液/电极的应用。
Mn doped barium zirconate titanate lead free ceramic with formula BaZr.045(MnxTi1-x).955O3for x = 0.00, 0.01, 0.02 and 0.03 has been prepared by solid-state reaction method. The single phase tetragonal structure was confirmed by X-ray diffraction (XRD) pattern using Rietveld refinement. Scanning electron microscopy (SEM) shows an inhomogeneous distribution of randomly oriented grains with some voids. Electrical conductivity of Mn doped BZT ceramics was studied using impedance analyzer in the temperature range 493K–673K over wide frequency window. The dispersion behaviour in electrical conductivity obeys Jonscher's double power law for Mn free compound, while it follows single power law for Mn doped compositions. Various parameters viz. dc conductivity (σdc), pre-exponential factor (A), frequency exponent (s) and activation energy (Ea) have been estimated by the theoretical fitting of experimental data. The reciprocal temperature dependence of dc conductivity follows the Arrhenius law and specifies thermally activated conduction mechanism. The obtained value of activation energy (Ea) evidences the conduction mechanism is induced by the migration of oxygen vacancies and oxide ions. All samples shows Negative temperature coefficient of resistance (NTCR) and hence exhibit semiconducting behaviour. The environmental friendly lead free ceramic can be exploit to design advanced materials and suitable for the fuel cell electrolyte/electrode applications.