Lead hafnate (PbHfO₃) perovskite powders synthesized by the oxidant peroxo method

Perovskite lead hafnate (PbHfO₃, PH) nanoparticles that were free from halides and organics were synthesized via the oxidant peroxo method. Stoichiometric amounts of hafnium nitrate (HfO(NO₃)₂) and lead nitrate (PbHfO₃) were dissolved in a diluted hydrogen peroxide (H₂O₂) aqueous solution, which was slowly added to a solution of H₂O₂ and ammonia (NH₃) (pH 11). The lead-hafnium precipitate obtained was filtered and washed, to eliminate all nitrate ions. The precipitate was dried, ground, and calcined at temperatures of 400°-900°C. A tetragonal intermediate phase was identified using X-ray diffractometry and Raman spectroscopy during the calcination process, followed by the crystallization of the orthorhombic PH phase at ∼700°C.