Chemical potential shift induced by double-exchange and polaronic effects inNd1−xSrxMnO3
Chemical potential shift induced by double-exchange and polaronic effects inNd1−xSrxMnO3
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DOI：
10.1103/physrevb.77.094422
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发表时间：
2007-10
影响因子：
3.7
通讯作者：
K. Ebata;M. Takizawa;K. Maekawa;A. Fujimori;H. Kuwahara;Y. Tomioka;Y. Tokura
中科院分区：
文献类型：
--
作者：
K. Ebata;M. Takizawa;K. Maekawa;A. Fujimori;H. Kuwahara;Y. Tomioka;Y. Tokura
通过芯级光电子能谱的测量，研究了Nd1-x(NSMO)的化学势随温度的变化。对于铁磁样品(x=0.4和0.45)，我们观察到在铁磁金属(FM)相的低温区，随着温度的降低，化学势有异常大的上移。这可以用双交换(DE)机制解释，如果$e_g$带被动力/局域Jahn-Teller效应分裂。这种位移在居里温度(T_C)附近被抑制，我们将其归因于从DE到晶格极化子区的交叉。
We have studied the chemical potential shift as a function of temperature in Nd$_{1-x}$Sr$_x$MnO$_3$ (NSMO) by measurements of core-level photoemission spectra. For ferromagnetic samples ($x=0.4$ and 0.45), we observed an unusually large upward chemical potential shift with decreasing temperature in the low-temperature region of the ferromagnetic metallic (FM) phase. This can be explained by the double-exchange (DE) mechanism if the $e_g$ band is split by dynamical/local Jahn-Teller effect. The shift was suppressed near the Curie temperature ($T_C$), which we attribute to the crossover from the DE to lattice-polaron regimes.