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 h of ball milling, large PZT particles were completely broken down, reducing its 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°C. Relatively low densities (∼91%) were achieved in stoichiometric samples, while in 3% lead excess samples sintered at 950°C for 30, 45, 60, 90 and 120 min using a fast firing process and a post-annealing treatment at 800°C for 4 h, densities of ∼97% of the theoretical were achieved. PZT nanostructured ceramics prepared under optimized processing conditions (60 h of powder milling, 950°C of sintering temperature, 60 min of sintering time and a post-annealing process at 800°C during 4 h) show high dielectric constant (ε′) values (900) and low dielectric loss (tan δ) at room temperature and a ferroelectric-paraelectric transition temperature at 375°C.