(Sr1-xCax)(3)Ru2O7 system: Optical and ARPES results

We present results of the first optical and angle-resolved photoemission (A RPES) measurements on the bilayer (Sr1-xCax)(3)Ru2O7, Or (Ca/Sr)327, system . While the real pan of optical conductivity, sigma(1)(omega), of Sr327 is similar to that of the high-T-c cuprates, sigma(1)(omega) of Ca377 can be d escribed almost entirely by a single broad Drude-like component. The ARPES results show a dramatic change of the low-energy electronic structure with increasing Ca doping from a normal band metal to a narrow-band marginally m etallic phase with a critical behavior at x similar or equal to 0.33. (C) 1 998 Elsevier Science Ltd. All rights reserved.