Development of Dysprosium Titanate Based Ceramics

Dysprosium titanate (Dy 2 TiO 5 ) based ceramic is one of the control rod materials for thermal reactors. This ceramic has been prepared by conventional mixing and calcination technique. The formation of Dy 2 TiO 5 phase from the Dy 2 O 3 –TiO 2 starting mixture has been found to be a two‐step process. In the first step, the formation of dysprosium dititanate (Dy 2 Ti 2 O 7 ) phase takes place at 700°C. This Dy 2 Ti 2 O 7 reacts at around 1100°C with remaining Dy 2 O 3 present in the mixture to form Dy 2 TiO 5 . The Dy 2 TiO 5 phase has three polymorphs (orthorhombic, hexagonal, and fluorite). The fluorite phase is reported to have lowest in‐service irradiation swelling characteristics when used as control rod elements in thermal reactors. In the present investigation, the fluorite polymorph of Dy 2 TiO 5 has been stabilized by doping with molybdenum trioxide.