Facile and Efficient Manufacture of Highly Densified MoO3 Ceramic Target for 99mTc Medical Isotopes Production by Novel Cold Sintering Process

99m Tc is one of the most widely used radioisotopes in nuclear medicine for diagnostic applications, with its supply critically dependent on the beta (β)-decay of the parent nuclide 99 Mo. To address this dependency, the cold sintering process has been introduced as a novel and facile technique to fabricate high-density MoO 3 ceramic targets for efficient 99 Mo production. It was explored in detail for the effects of transient liquid solutions, sintering temperature, uniaxial pressure, holding time, and additive formulation on the densification of raw MoO 3 powder. The results show that the typical transition solution of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O and H 2 O mixture was most conducive to densifying MoO 3 material. The optimum conditions for cold sintering were under temperature of 200 °C, pressure of 500 MPa, holding time of 10 min, and transient aqueous solution of 10 wt.% (NH 4 ) 6 Mo 7 O 24 ·4H 2 O and 10 wt.% H 2 O. After further annealing cold-sintered MoO 3 at 600 °C, pure MoO 3 ceramic was obtained with the disappearance of the second phase. The pure MoO 3 ceramic target had a relative density of 95.48%, compressive strength of 118.01 MPa, and micro-Vickers hardness of 0.472 GPa. All these results suggested that cold sintering could be an energy-saving economical and efficient technique on the densification of MoO 3 for preparation its ceramic target, which are expected to inspire new insights to establish more practical technologies for 99 Mo and 99m Tc productions.