THE EFFECT OF HEATING RATE ON THE PROPERTIES OF PMN RELAXOR CERAMICS

The effect of heating rate on the properties of ferroelectric lead mag nesium niobate ceramics during calcining and sintering processes was r eported in this investigation. Perovskite phase content, density, micr ostructure, and the dielectric properties of PMN ceramics with the hea ting rate from 2 degrees C/min to 30 degrees C/min were studied. Perov skite phase content was affected by heating rate, especially on the su rface exposed to air. A slow heating rate caused more evaporation of P bO and resulted in porous ceramics with small grains. Increasing PMN c ontent, density, and grain size with increasing heating rate made the dielectric constant increase.