The phase-diagram of Ca2-xSrxRuO4: Relation between crystal distortions and physical properties

The phase-diagram of Ca2-x.SrxRuO4 has been studied by several diffraction techniques as function of concentration, temperature, pressure and magnetic field. The substitution of Sr through the smaller Ca induces a series of structural phase transitions with a strong impact on the physical properties. The spin triplet superconductor Sr 2RuO4 exhibits an undistorted crystal structure, and the Mott-insulator Ca2RuO4 strong structural distortions. For intermediate structural distortions samples stay metallic but with outstanding properties. Throughout the phase diagram we find a close coupling between the crystal structure on one side and magnetic and electronic behavior on the other side. © 2005 Materials Research Society