Ho3+-doped Y3NbO7 transparent ceramic elaborated by air pre-sintering and post-HIP treatment as potential LASER gain material at 2 μm

In the framework of the development of new laser materials at the lowest limit of the mid-IR range, the cubic Y3NbO7 matrix has been doped by trivalent holmium. Fine powders were prepared through a liquid phase synthesis and highly densified using a two-stage sintering process: i) natural sintering was performed in air to reach relative density higher than 95%; ii) Hot Isostatic Pressure was applied to obtain fully dense and, consequently, transparent ceramics. The resulting microstructures were examined and then related to sintering parameters such as temperature and pressure. Refractive index, transmission and luminescence properties were measured and presented for the first time on a bulk material. These encouraging results showed that the Ho3+- doped Y3NbO7 compound is a promising potential candidate as a new laser material.