“…In recent years, there have been many studies on the methods to increase the flexural strength of sapphire at high temperatures, such as ion implantation [7], thermal annealing [8], neutron irradiation [9] and coating with protective films [10]. Demaree et al [11] investigated the mechanical benefit of using highly-polished single-crystal c-axis sapphire implanted with Cr + , Ti + and Si + ions both at room temperature and at 800°C.…”