Growth of bulk single crystal ScAlMgO4 boules and GaN films on ScAlMgO4 substrates for GaN-based optical devices, high-power and high-frequency transistors

•Production of a ScAlMgO4 single crystal by the Cz technique was demonstrated.•2-inches ScAlMgO4 crystal was confirmed to be without dislocation by XRT.•Thick GaN film was grown on a ScAlMgO4 substrate by HVPE.•The GaN film was readily separated from the substrate using its cleavability.•ScAlMgO4 substrate opens the way to produce good GaN free-standing wafers.