The evolution of the electronic properties of electron-doped $({\mathrm{Sr}}_{1-x}{\mathrm{La}}_x{)}_2{\mathrm{IrO}}_4$ is experimentally explored as the doping limit of La is approached. As electrons are introduced, the electronic ground-state transitions from a spin-orbit Mott phase into an electronically phase separated state, where long-range magnetic order vanishes beyond $x=0.02$ and charge transport remains percolative up to the limit of La substitution ($x\approx 0.06$). In particular, the electronic ground state remains inhomogeneous even beyond the collapse of the parent state's long-range antiferromagnetic order, while persistent short-range magnetism survives up to the highest La-substitution levels. Furthermore, as electrons are doped into ${\mathrm{Sr}}_2{\mathrm{IrO}}_4$, we observe the appearance of a low-temperature magnetic glasslike state intermediate to the complete suppression of antiferromagnetic order. Universalities and differences in the electron-doped phase diagrams of single-layer and bilayer Ruddlesden-Popper strontium iridates are discussed.

• Received 23 June 2015
• Revised 28 July 2015

DOI:https://doi.org/10.1103/PhysRevB.92.075125