Structure symmetry determination and magnetic evolution in Sr2Ir1-xRhx O4

We use single-crystal neutron diffraction to determine the crystal structure symmetry and the magnetic evolution in the rhodium-doped iridates Sr2Ir1-xRhxO4 (0≤x≤0.16). Throughout this doping range, the crystal structure retains a tetragonal symmetry (space group I41/a) with two distinct magnetic Ir sites in the unit cell forming staggered IrO6 rotation. Upon Rh doping, the magnetic order is suppressed and the magnetic moment of Ir4+ is reduced from 0.21μB/Ir for x=0 to 0.18μB/Ir for x=0.12. The magnetic structure at x=0.12 is different from that of the parent compound, while the moments remain in the basal plane.