  Single crystals of iridates are usually grown by a flux method well above the
boiling point of the SrCl2 solvent. This leads to non-equilibrium growth
conditions and dramatically shortens the lifetime of expensive Pt crucibles.
Here, we report the growth of Sr2IrO4, Sr3Ir2O7 and SrIrO3 single crystals in a
reproducible way by using anhydrous SrCl2 flux well below its boiling point. We
show that the yield of the different phases strongly depends on the
nutrient/solvent ratio for fixed soak temperature and cooling rate. Using this
low-temperature growth approach generally leads to a lower
temperature-independent contribution to the magnetic susceptibility than
previously reported. Crystals of SrIrO3 exhibit a paramagnetic behavior that
can be remarkably well fitted with a Curie-Weiss law yielding physically
reasonable parameters, in contrast to previous reports. Hence, reducing the
soak temperature below the solvent boiling point not only provides more stable
and controllable growth conditions in contrast to previously reported growth
protocols, but also extends considerably the lifetime of expensive platinum
crucibles and reduces the corrosion of heating and thermoelements of standard
furnaces, thereby reducing growth costs.
