Chemical potential shift and spectral-weight transfer inPr1−xCaxMnO3revealed by photoemission spectroscopy

摘要: We have studied the chemical potential shift and changes in electronic density of states near Fermi level ($E_F$) as a function carrier concentration Pr$_{1-x}$Ca$_x$MnO$_3$ (PCMO, $0.2 \le x 0.65$) through measurements photoemission spectra. The results showed that was suppressed for $x \agt 0.3$, where charge exchange (CE)-type antiferromagnetic charge-ordered state appears at low temperatures. consider this observation to be related self-organization such stripe formation on microscopic scale composition range. Together with previous monotonous La$_{1-x}$Sr$_x$MnO$_3$, we conclude tendency toward increases decreasing bandwidth. In valence band, spectral weight Mn 3$d$ $e_g$ electrons PCMO transferred from $\sim$ 1 eV below $E_F$ region hole doping, leading finite intensity even paramagnetic insulating phase probably self-organization. spite transport behavior is consistent fluctuations involving ferromagnetic metallic states.