MgAl2O4 spinel powders from oxide one pot synthesis (OOPS) process for ceramic humidity sensors

MgAl2O4 spinel powders can be prepared via the oxide one pot synthesis (OOPS) process. Porous ceramic oxide bodies can be produced with these powders and used as humidity-sensing materials. Pellets were characterized by SEM and their electrical properties were measured using impedance spectroscopy in the frequency range from 10(-2) to 10(5) Hz at different relative humidity (RH) levels in the range 4-90%. The spinel pellets made of powder from the OOPS process exhibited good humidity sensitivity with a linear response of the logarithm of resistance with RH in the whole RH range tested. (C) 2000 Elsevier Science Ltd. All rights reserved.