Structural studies of rhodium doped Sr2RuO4 Original Research Article

The influence of Rh doping on the structure of Sr2RuO4 has been investigated using neutron powder diffraction methods. The metallic Ru rich compounds adopt a regular K2NiF4-type structure, space group I4/mmm, with Ru–O–Ru bond angles of 180°. The structures of the nonmetallic Rh rich compounds crystallise in space group I4/acd and are characterised by tilting of the MO6 octahedra reducing the Ru–O–Ru angle to about 160°. Irrespective of Rh content the MO6 polyhedra are not regular octahedra but are elongated along the c direction. The temperature dependence of the structure of Sr2Ru0.9Rh0.1O4 was investigated and revealed this elongation to be weakly temperature dependent.