Structure and electrical resistivity of (1-x)La2NiO4+δ/xBaTiO3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(1 - x)\hbox {La}_{2}\hbox {NiO}_{4+\delta }/x\hbox {BaTiO}_{3}$$\end{document} composites (x=0.05,0.1,0.2,0.3,0.5\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x = 0.05, 0.1, 0.2, 0.3, 0.5$$\end{document}) produced by combining the sol–gel and ceramic sintering methods have been investigated. Among the samples sintered at temperature 1300∘C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1300^{\circ }\hbox {C}$$\end{document} for 16 h, the metal–insulator transition (MIT) temperature of x=0.1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x = 0.1$$\end{document} sample, which is TMI=700K\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}} = 700~\hbox {K}$$\end{document}, is lower than the MIT temperature (800 K) of the pristine La2NiO4+δ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {La}_{2}\hbox {NiO}_{4+\delta }$$\end{document} (LNO) perovskite. Reduction of resistivity of x≤0.3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x \le 0.3$$\end{document} composite is mainly due to decrease of the scattering of electrical carriers by composite large grain boundaries and the structural change of the LNO component. The temperature dependence of the resistivity of (1-x)La2NiO4+δ/xBaTiO3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(1 - x)\hbox {La}_{2}\hbox {NiO}_{4+\delta }/x\hbox {BaTiO}_{3}$$\end{document} composites is well-explained by a two conducting component model consisting of small polarons (SP) and large polarons (LP). A crossover between SP and LP with increasing temperature is described by the probability volume fraction function f for SP and 1-f\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1 - f$$\end{document} for LP, which are equal to 1/2 at transition temperature TMI\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}}$$\end{document}. The observed lowest resistivity ρ=11mΩ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho =11~\hbox {m}\Omega $$\end{document} cm for x=0.1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x = 0.1$$\end{document} sample corresponds to the lowest SP thermal activation energy Ea\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E_{\mathrm{a}}$$\end{document}, the contributions of residual and phonon resistivities at TMI\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}}$$\end{document}. The MIT of these composites satisfies approximately the Mott criterion.

中文翻译：

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$$\hbox {La}_{2}\hbox {NiO}_{4+\delta }/\hbox {BaTiO}_{3}$$ 复合材料中的金属-绝缘体跃迁和从小到大的极化子交叉

这是 TMI=700K\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength {\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}} = 700~\hbox {K}$$\end{document}，低于 MIT 温度（800 K）原始的 La2NiO4+δ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength {\oddsidemargin}{-69pt} \begin{document}$$\hbox {La}_{2}\hbox {NiO}_{4+\delta }$$\end{document} (LNO) 钙钛矿。x≤0的电阻率降低。1$$\end{document} 样品对应最低 SP 热活化能 Ea\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy } \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E_{\mathrm{a}}$$\end{document}，残差和声子的贡献TMI\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\ oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}}$$\end{document}。这些复合材料的 MIT 近似满足莫特准则。TMI\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{ 的残余和声子电阻率的贡献upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}}$$\end{document}。这些复合材料的 MIT 近似满足莫特准则。TMI\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{ 的残余和声子电阻率的贡献upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T_{\mathrm{MI}}$$\end{document}。这些复合材料的 MIT 近似满足莫特准则。