Crystal growth of Sr2IrxRu1−xO4 for x⩽0.4

•Single crystals of Sr2IrxRu1−xO4 synthesized via floating zone method.•Large, homogeneous samples span reported Lifshitz transition.•High pressure environment decreases volatility of RuO2 and IrO2. We describe the synthesis of crystalline Sr2IrxRu1−xO4 via a floating zone growth technique. We find that the use of a high pressure gas environment (70 bar mixed O2 and Ar) greatly decreases the volatility and loss of the IrO2 and RuO2 reactants. The resultant gram-sized samples are more uniform in composition than comparable flux-grown crystals.