Structural and magnetic aspects of the metal insulator transition in   Ca$_{2-x}$Sr$_x$RuO$_4$
  The phase diagram of Ca$_{2-x}$Sr$_x$RuO$_4$ has been studied by neutron diffraction on powder and single-crystalline samples. The experiments reveal antiferromagnetic order and structural distortions characterized by tilts and rotations of the RuO$_6$-octahedra. There is strong evidence that the structural details of the isovalent samples tune the magnetic as well as the electronic behavior. In particular we observe for low Sr-concentration a metal insulator transition associated with a structural change and magnetic ordering. 
O. Friedt, M. Braden, G. Andre, P. Adelmann, S.Nakatsuji, and Y. Maeno