Effects of substitutions of Nd 3+ for Sr 2+ on the properties of SrBi 2 Nb 2 O 9 ceramics and their mechanism
Effects of substitutions of Nd 3+ for Sr 2+ on the properties of SrBi 2 Nb 2 O 9 ceramics and their mechanism
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DOI：
10.7498/aps.58.5790
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发表时间：
2009-08
期刊：
影响因子：
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通讯作者：
Sun Lin;Chu Junhao;Yang Pingxiong;Feng Chu-De
中科院分区：
文献类型：
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作者：
Sun Lin;Chu Junhao;Yang Pingxiong;Feng Chu-De
采用传统固相反应法制备了（Sr1-3x/2Ax/2Ndx）Bi2Nb2O9（x=0，0.05，0.1和0.2）陶瓷，研究了Nd3+替代Sr2+对SrBi2Nb2O9陶瓷性能的影响及其机理。结果表明，这些Nd掺杂样品的介电常数和损耗的温度谱具有明显的离子弛豫极化特征。 Nd3+部分替代Sr2+导致剩余极化率（Pr）略有降低，压电系数d33增加，根据铁电热力学理论，这可归因于样品介电常数的增加。拉曼光谱显示（Sr1-3x/2Ax/2Ndx）Bi2Nb2O9样品的居里温度（TC）没有变化，这可能是由于NbO6八面体畸变没有明显变化所致。对于（Sr1-3x/2Ax/2Ndx）Bi2Nb2O9陶瓷，用Nd3+替代Sr2+，提高了介电常数er、压电系数d33和机电耦合系数Kp，降低了机械品质因数Qm，但不改变谐波频率值的温度系数。
（Sr1-3x/2Ax/2Ndx）Bi2Nb2O9 （x=0，0.05，0.1 and 0.2） ceramics are prepared by traditional solid-reaction method， and effects of substitutions of Nd3+ for Sr2+ on the properties of SrBi2Nb2O9 ceramics and their mechanism are investigated. The results show that the temperature spectra of dielectric constant and loss for these Nd-doped samples are obviously characteristic of ion relaxor polarization. The partial substitution of Nd3+ for Sr2+ leads to the slight reduction in remanent polarization （Pr） and the increase in piezoelectric coefficient d33， which can be attributed to the increase in dielectric constant of samples according to ferroelectric thermodynamics theory. Raman spectrum shows that no change in the Curie temperature （TC） of （Sr1-3x/2Ax/2Ndx） Bi2Nb2O9 samples is observed， which might result from no appreciable variation in NbO6 octahedron distortion. For （Sr1-3x/2Ax/2Ndx） Bi2Nb2O9 ceramics， the substitution of Nd3+ for Sr2+ increases permittivity er， piezoelectric coefficient d33，and electromechanical coupling coefficient Kp and reduces mechanical quality factor Qm, but it does not change temperature coefficient of harmonic frequency value.