Structure and properties of luminescent ceramics GdNbO4 obtained by usual technology and by hot pressing

Fine crystalline GdNbO4 powders have been synthesized by sol-gel method. Usual ceramic technology and hot pressing have been applied to obtain GdNbO4 ceramic samples. Morphological particularities have been studied in GdNbO4 ceramics microstructure. Ceramics strength characteristics (strength, Young’s modulus) have been evaluated for the first time. A mode I stress intensity factor KIC have been determined (note that the factor is a crack resistance criterion). Photoluminescence characteristics have been compared in GdNbO4 ceramics before and after vacuum annealing in the visible region.