We present results of the first optical and angle-resolved photoemission study on a layered ruthenium oxide system with various Ca/Sr substitution levels. Using two-plane (Sr1-xCax)3Ru2O7 and one-plane Ca2RuO4 crystals we were able to study evolution of the electronic properties in a range from a band metal 8(Sr3Ru2O7) to a “bad” metal (Ca3Ru2O7) to a Mott-Hubbard insulator (Ca2)RuO4). Apart from a Mott-Hubbard metal-insulator transition (MIT), we have uncovered a qualitative change of the electronic properties at a critical x=0.33. We suggest that the latter is a result of a quantum phase transition into an antiferromagnetic phase that precedes the real Mott-Hubbard MIT.
ASJC Scopus subject areas
- Physics and Astronomy(all)