Characterization of nanostructured ceramics prepared by both high energy ball milling and fast firing sintering processes

Abstract

High-energy ball milling technique was successfully applied to calcinated lead zirconate titanate (PZT 60/40) powders. After 20 hours of ball milling, large PZT particles were completely broken down and, reducing it initial size in three orders of magnitude. Experimental results show a huge sinterability enhancement of the PZT powders by using this technique, achieving its maximum sintering rate at ~ 800 ºC. Relatively low densities (~91%) were achieved in stoichiometric samples, while in 3% lead excess samples sintered at 950o C for 30, 45, 60, 90 and 120 minutes by using a fast firing process and a post-annealing treatment at 800 ºC for 4 hours densities of ~ 97 % of the theoretical were achieved. PZT nanostructured ceramics prepared under optimized processing conditions (60 hours of powder milling, 950ºC of sintering temperature, 60 minutes of sintering time and a post-annealing process at 800ºC during 4 hours) show high dielectric constant (ε´) values (900) and low dielectric loss (tanδ) at room temperature and a ferroelectric-paraelectric transition temperature at 375ºC.