Electrical conduction in La0.85Sr0.15MnO3:Agx ceramics with large room-temperature TCR
Electrical conduction in La0.85Sr0.15MnO3:Agx ceramics with large room-temperature TCR
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具有大室温 TCR 的 La0.85Sr0.15MnO3:Agx 陶瓷中的导电
DOI：
10.1016/j.ceramint.2019.08.113
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发表时间：
2019
影响因子：
5.2
通讯作者：
Liu Xiang
中科院分区：
文献类型：
--
作者：
Liu Yang;Sun Tao;Dong Gang;Zhang Shuai;Liu Xiang
摘要：采用溶胶-凝胶法制备了La 0.85 Sr 0.15 mno3: Ag x （LSMO: Ag x, 0≤x≤0.5）多晶陶瓷。所有样品均呈r3 - c空间群的菱面体钙钛矿结构。随着Ag含量的增加，陶瓷的晶粒尺寸增大，电阻率相应降低。当x= 0.4时，室温（289.2 K）下电阻率温度系数（TCR）达到22.9% K−1。有趣的是，电阻率-温度（ρ-T）实验数据分析表明，整个温度区域的传导机制与理论渗流模型完全吻合。这表明LSMO: Ag x陶瓷的电输运性质主要受畴、晶界（GBs）和近道类自旋依赖散射的影响。它还证明了LSMO: Ag x陶瓷中顺磁性（FM）和铁磁性（PM）相的共存。ρ-T和扫描电镜（SEM）结果证实了Ag的引入减弱了这些散射效应。
Abstract Polycrystalline La 0.85 Sr 0.15 MnO 3: Ag x (LSMO: Ag x, 0≤ x≤ 0.5) ceramics were synthesized using sol-gel procedure. All specimens showed rhombohedral perovskite structures in R 3‾ c space group. As the amount of Ag increased, grain size of ceramics increased, and resistivity accordingly decreased. Large temperature coefficient of resistivity (TCR) of 22.9% K− 1 was obtained at room temperature (289.2 K) for x= 0.4. Interestingly, analyses of resistivity-temperature (ρ-T) experimental data showed that conduction mechanism over entire temperature region perfectly matched theoretical percolation model. This reveals that electrical transport properties of LSMO: Ag x ceramics are mainly affected by domains, grain boundaries (GBs), and Kondo-like spin-dependent scattering. It also demonstrates the coexistence of paramagnetic (FM) and ferromagnetic (PM) phases in LSMO: Ag x ceramics. The ρ-T and scanning electron microscopy (SEM) results confirmed that the introduction of Ag weakened these scattering effects.