PHYS07200604007 Manas Kumar Dala - Homi Bhabha National ...
PHYS07200604007 Manas Kumar Dala - Homi Bhabha National ...
PHYS07200604007 Manas Kumar Dala - Homi Bhabha National ...
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spectroscopy and O K edge x-ray absorption spectroscopy we have studied the temperature<br />
dependence of the near Fermi level electronic structure in the electron doped<br />
CMR, Ca 0.86 Pr 0.14 MnO 3 . We found that the temperature dependent changes in the<br />
electronic structure is consistent with the conductivity behavior of the electron doped<br />
systems in general. As the temperature is lowered from 293 K a feature due to the e g<br />
states starts appearing near the E F . This increase in the DOS is a signature of the<br />
semi-metallic behavior of the sample in the range 110 - 300 K. Surprisingly, though<br />
the resistivity measurement on this sample showed an insulating behavior below its<br />
transition temperature T c (110 K), the intensity of this feature further increases below<br />
the T c . Further, we have found an increase in the e g band width (W) also at<br />
low temperatures. It was also interesting to note that the increase in the near E F<br />
DOS in this compound is apparently different in nature from that associated with the<br />
pseudogap formation in the other systems like Pr 1−x Sr x MnO 3 . We have discussed our<br />
results from the point of view of phase sepation models considering the temperature<br />
dependent structural changes and consequent localization of the electrons in a narrow<br />
e g band.<br />
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