A novel durable spinel-type ZnGa2O4 transparent ceramic with wide transmission range

A novel ZnGa2O4 transparent ceramic was prepared from synthesized single-phase powders by pressureless sintering combined with hot isostatic pressing (HIP) and a post-annealing treatment. The transparent ceramic was fully densified with the average grain size of ∼3.2 μm, which possesses outstanding optical properties, including a high in-line transmittance of 82.03% at 2 μm comparable to its single crystal counterpart (82.52% at 2 μm) and a wide transmission range (0.27-8.7 μm). Such an extended infrared transmission range could be attributed to the lower phonon frequency of ZnGa2O4 spinel. This material also exhibits excellent mechanical properties of Vickers hardness (10.56 ± 0.08 GPa), Young's modulus (227.04 GPa) and fracture toughness (1.83 ± 0.08 MPa/m1/2), as well as high thermal conductivity (19.46 W/m•K) at ambient temperature. [Display omitted]