Scanning Tunneling Spectroscopy on Pr0.68Pb0.32MnO3 single crystals

作者：Roessler S^*; Ernst S; Padmanabhan B; Elizabeth Suja; Bhat H L; Wirth S; Steglich F

来源：IEEE Transactions on Magnetics, 2007, 43(6): 3064-3066.

DOI：10.1109/TMAG.2007.892566

• colossal magnetoresistance (CMR)
• manganites
• metal-insulator transition
• scanning tunneling spectroscopy

Scanning tunneling microscopy/spectroscopy studies were carried out on single crystals of colossal magnetoresistive manganite Pr0.68Pb0.32MnO3 at different temperatures in order to probe their spatial homogeneity across the metal-insulator transition temperature TM-I(similar to 255 K). A metallic behavior of the local conductance was observed for temperatures T < TM-I. Zero bias conductance (dI/dV)v=(0), which is directly proportional to the local surface density of states at the Fermi level, shows a single distribution at temperatures T < 200 K suggesting a homogeneous electronic phase at low temperatures. In a narrow temperature window of 200 K < T < TM-I, however, an inhomogeneous distribution of (dI/dV)v=(0) has been observed. This result gives evidence for phase separation in the transition region in this compound.

• 出版日期2007-6