Dielectric catastrophe at the magnetic field induced insulator to metal transition in Pr1-xCaxMnO3(x=0.30, 0.37) crystals
Dielectric catastrophe at the magnetic field induced insulator to metal transition in Pr1-xCaxMnO3(x=0.30, 0.37) crystals
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DOI：
10.1140/epjb/e2006-00282-x
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发表时间：
2006-07-01
影响因子：
1.6
通讯作者：
Simon, Ch.
中科院分区：
文献类型：
--
作者：
Kundys, B.;Bellido, N.;Simon, Ch.
同时测定了不同掺杂Pr1-xCaxMnO3晶体的介电常数和电阻率随磁场的变化规律。在渗流阈值附近，介质介电常数显著增大。在整个绝缘体到金属过渡过程中，介电性能和导电性能是相互相关的，证明了介电突变现象。数据在麦克斯韦-加内特理论和莫特-哈伯德理论的框架下分析，归因于强库仑相互作用的作用。
The dielectric permittivity and resistivity have been measured simultaneously as a function of magnetic field in Pr1-xCaxMnO3 crystals with different doping. A huge increase of dielectric permittivity was detected near percolation threshold. The dielectric and conductive properties are found to be mutually correlated throughout insulator to metal transition evidencing the dielectric catastrophe phenomenon. Data are analyzed in a framework of Maxwell-Garnett theory and the Mott-Hubbard theory attributed to the role of strong Coulomb interactions.