Data for Paper "Tricritical phenomenon and H-T phase diagram in a single crystal of the double-perovskite iridate La2ZnIrO6"

Single crystals of La2ZnIrO6 were grown by the KF flux method. A polycrystalline sample of La2ZnIrO6 was first prepared by the solid state reaction using stoichiometric starting materials La2O3 (99.9%, Alfa Aesar) and IrO2 (99.9%). Then, single crystals were grown by combining the polycrystalline sample with KF flux in a ratio of 1 : 300. After being heated to 1100 ◦C and annealed for 5 h, the as-grown sample was slowly cooled down to 850 ◦C at a rate of 2 ◦C/h. The single crystals were obtained from the flux by dissolving the flux in water. The chemical compositions were carefully checked by the energy dispersive x-ray (EDX) spectrometry. The crystal structure and orientations were determined by the Rigaku Gemini S Ultra four-circle single crystal x-ray diffractometer (XRD). The magnetization was measured using a quantum design vibrating sample magnetometer (SQUID-VSM). The no-overshoot mode was applied to ensure a precise magnetic field. The magnetic field was relaxed for two minutes before data collection. For the measurement of initial isothermal magnetization, the sample was first heated adequately above the phase transition temperature for 10 min, then cooled to the target temperature under zero magnetic field.