Neutron diffraction and magnetisation studies of Sr2RuO4 below 2 K

High resolution neutron powder diffraction and magnetisation measurements have been carried out on the superconductor, Sr2RuO4. The powder diffraction data has been refined at high and low temperatures to obtain lattice parameters below the superconducting transition temperature(1.15 K) and at elevated temperatures where Sr2RuO4 is used as a substrate for the deposition of YBa2Cu3O7 thin films. No evidence has been found for any lattice distortions between 100 mK and 2 K in Sr2RuO4. Magnetisation measurements between 0.7 K and room temperature has indicated the onset of superconductivity at 1.15 K.