Improved electrical transport properties of polycrystalline La(0.8)(Ca(0.12)Sr(0.08))MnO(3) ceramics by Ag(2)O doping.
Improved electrical transport properties of polycrystalline La(0.8)(Ca(0.12)Sr(0.08))MnO(3) ceramics by Ag(2)O doping.
复制标题
Ag2O掺杂改善多晶La-0.8(Ca0.12Sr0.08)MnO3陶瓷的电输运性能
DOI：
10.1039/c8ra08463g
复制
发表时间：
2019-01-14
期刊：
影响因子：
3.9
通讯作者：
Liu, Xiang
中科院分区：
文献类型：
--
作者：
Dong, Gang;Sun, Tao;Ji, Fuquan;Liu, Yang;Zhang, Shuai;Yang, Zhiheng;Yu, Xiaohan;Duan, Yunbiao;Li, Zhidong;Liu, Xiang
采用溶胶-凝胶法合成了La0.8（Ca0.12Sr0.08）MnO 3：mol%Agx（LCSMO：Agx，x = 0，0.1，0.2，0.3，0.4）多晶陶瓷。研究了LCSMO：Agx陶瓷的结构、电性能和磁性能。X射线衍射（XRD）分析表明，所有样品均为正交晶系，空间群为Pnma。随着Ag掺杂量（x）的增加，LCSMO：Agx样品的晶粒尺寸增大，晶界数量相应减少。同时，Mn-O键长和Mn-O-Mn键角也发生了相应的变化，导致晶格常数（a，B，c）略有增加，晶胞体积（V）略有增大。对于x = 0.3的LCSMO：Agx样品，电阻温度系数（TCR）和磁阻温度系数（MR）的最佳值分别达到16.22%K −1（265.1 K）和42.07%K −1（270.48 K）。此外，对ρ-T曲线的拟合分析表明，实验数据与理论计算数据吻合较好。在T < TMI（金属-绝缘体转变温度）范围内，通过电子-磁振子散射、电子-电子散射和电子-声子散射，阐明了LCSMO：Agx的导电机理。在T > TMI区，用绝热小极化子跳跃模型解释了电阻率数据。此外，在整个温度范围内，称为逾渗模型的唯象方程被用来解释的电阻率数据和相分离机制的铁磁金属（FM）和顺磁绝缘（PI）相。结果表明，Ag的掺杂改变了A位（La、Ca和Sr离子）的平均离子半径、Mn-O-Mn键角和Mn-O键距，从而改善了LCSMO：Agx样品的电学性能。此外，晶粒尺寸增加，这导致在LCSMO：Agx多晶陶瓷中的Mn 4+离子浓度和GBs连接性的改善。采用溶胶-凝胶法合成了La0.8（Ca0.12Sr0.08）MnO 3：mol%Agx（LCSMO：Agx，x = 0，0.1，0.2，0.3，0.4）多晶陶瓷。
Polycrystalline La0.8(Ca0.12Sr0.08)MnO3:mol%Agx (LCSMO:Agx, x = 0, 0.1, 0.2, 0.3 and 0.4) ceramics were synthesized by the sol–gel technique. Structural, electrical and magnetic properties of the LCSMO:Agx ceramics were investigated in detail. X-ray diffraction (XRD) data analyses revealed that all the samples were crystalized in the orthorhombic structure with space group of Pnma. With the increase in Ag doping (x), the grain sizes of the LCSMO:Agx samples increased and the amount of grain boundaries (GBs) decreased accordingly. At the same time, the Mn–O bond distance and the Mn–O–Mn bond angles changed correspondingly, leading to the slight increase in the lattice constants (a, b and c) and slight expansion of cell volume (V). For the LCSMO:Agx sample with x = 0.3, the optimal values of temperature coefficient of resistivity (TCR) and magnetoresistance (MR) reached 16.22% K−1 (265.1 K) and 42.07% K−1 (270.48 K), respectively. In addition, the fitting analysis of ρ–T curves showed that the experimental data were consistent with the theoretical calculation data. In the T < TMI (metal-insulator transition temperature) region, the electrical conduction mechanism of LCSMO:Agx was clarified by electron-magnon, electron–electron and electron-phonon scattering. In the T > TMI region, the resistivity data were interpreted by using the adiabatic small-polaron hopping model. Furthermore, in the entire temperature range, the phenomenological equation called the percolation model was used to explain the resistivity data and the phase-separation mechanism of ferromagnetic metallic (FM) and paramagnetic insulating (PI) phases. All the obtained results indicated that the improvement in the electrical properties of the LCSMO:Agx samples was attributed to the doping of Ag, which changed the A-site (La, Ca and Sr ions) average ion radius, the Mn–O–Mn bond angles and the Mn–O bond distance. In addition, the grain size increased, which led to improvement in the Mn4+ ion concentration and the GBs connectivity in the LCSMO:Agx polycrystalline ceramics. Polycrystalline La0.8(Ca0.12Sr0.08)MnO3:mol%Agx (LCSMO:Agx, x = 0, 0.1, 0.2, 0.3 and 0.4) ceramics were synthesized by the sol–gel technique.
登录
查看更多内容
影响因子：
4
作者：
Mahesh, R;Mahendiran, R;Rao, CNR
通讯作者：
Rao, CNR
Ag掺杂对La0.625(Ca0.315Sr0.06)MnO3陶瓷电磁性能的影响
影响因子：
5.2
作者：
Jiang, Jun;Zhao, Shuang;Liu, Xiang
通讯作者：
Liu, Xiang
影响因子：
3.2
作者：
Li, G;Zhou, HD;Wang, ZD
通讯作者：
Wang, ZD
影响因子：
64.8
作者：
Xiong, ZH;Wu, D;Shi, J
通讯作者：
Shi, J
影响因子：
2.1
作者：
Das, S;Dey, TK
通讯作者：
Dey, TK