Mechanically Activating Nucleation and Growth of Complex Perovskites

✍ Scribed by John Wang; J.M. Xue; D.M. Wan; B.K. Gan

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 363 KB
• Volume: 154
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.8782

✦ Synopsis

Mechanical activation of the constituent oxides at room temperature led to the formation of nanocrystalline Pb-based relaxor ferroelectrics and piezoelectrics of complex perovskite structure. The activation-triggered occurrence of complex perovskites, such as Pb(Mg 1/3 Nb 2/3 )O 3 , 0.9[0.4Pb(Mg 1/3 Nb 2/3 )O 3 + 0.6Pb(Zn 1/3 Nb 2/3 )O 3 ]+0.1PbTiO 3 , and Pb(Zr 0.52 Ti 0.48 )O 3 , in the mixed oxide compositions and in an amorphous precursor derived from coprecipitation proceeds via a process involving nucleation and subsequent growth of perovskite crystallites with increasing degree of mechanical activation. This is fundamentally di4erent from the one or more interfacial reactions and di4usions responsible for a thermally activated solid state reaction occurring at an elevated temperature. Nucleation occurs in a highly activated state, where a degree of amorphization has taken place, and the subsequent growth proceeds as a result of the constant collisions and rearrangement of perovskite nuclei.