Metal-to-insulator transition inLa1−xBaxTiO3
Metal-to-insulator transition inLa1−xBaxTiO3
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DOI：
10.1103/physrevb.64.045113
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发表时间：
2001-07
影响因子：
3.7
通讯作者：
V. Fritsch;J. Hemberger;M. Brando;A. Engelmayer;S. Horn;M. Klemm;G. Knebel;F. Lichtenberg;P. Mandal;F. Mayr;M. Nicklas;A. Loidl
中科院分区：
文献类型：
--
作者：
V. Fritsch;J. Hemberger;M. Brando;A. Engelmayer;S. Horn;M. Klemm;G. Knebel;F. Lichtenberg;P. Mandal;F. Mayr;M. Nicklas;A. Loidl
The ferroelectric insulator ${\mathrm{BaTiO}}_{3}$ can be electron-doped by substitution of divalent ${\mathrm{Ba}}^{2+}$ with trivalent ${\mathrm{La}}^{3+},$ creating d states at the transition-metal sites. The successive filling of the $3d$ Ti band initiates a sequence of electronic transitions. First, the system undergoes an Anderson-type insulator-to-metal-transition into a paramagnetic and metallic state, and second, a correlation-induced antiferromagnetic and insulating phase is established for La-rich concentrations. Ceramic ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{TiO}}_{3}$ samples covering the whole concentration range were systematically examined utilizing measurements of resistivity, specific heat, and magnetic susceptibility in the temperature range $1.8lTl300\mathrm{K}.$ The concentration dependence of the Sommerfeld coefficient $\ensuremath{\gamma}$ and the Pauli spin susceptibility was systematically investigated. The temperature dependence of the resistivity was studied in detail. In addition a $(T,x)$ phase diagram of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{TiO}}_{3}$ was constructed.
The ferroelectric insulator ${\mathrm{BaTiO}}_{3}$ can be electron-doped by substitution of divalent ${\mathrm{Ba}}^{2+}$ with trivalent ${\mathrm{La}}^{3+},$ creating d states at the transition-metal sites. The successive filling of the $3d$ Ti band initiates a sequence of electronic transitions. First, the system undergoes an Anderson-type insulator-to-metal-transition into a paramagnetic and metallic state, and second, a correlation-induced antiferromagnetic and insulating phase is established for La-rich concentrations. Ceramic ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{TiO}}_{3}$ samples covering the whole concentration range were systematically examined utilizing measurements of resistivity, specific heat, and magnetic susceptibility in the temperature range $1.8lTl300\mathrm{K}.$ The concentration dependence of the Sommerfeld coefficient $\ensuremath{\gamma}$ and the Pauli spin susceptibility was systematically investigated. The temperature dependence of the resistivity was studied in detail. In addition a $(T,x)$ phase diagram of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{TiO}}_{3}$ was constructed.