Dielectric behavior of a lead-free electroceramics Ba1-xEr2x/3(Ti1-yZry)O-3

Lead-free electroceramics samples of composition Ba1-xEr2x/3(Ti1-yZry)O-3 (BETZ) with x = 0.01 and 0.02 and 0.20 <= y <= 0.35 have been elaborated by solid-state reaction technique. X-ray diffraction at room temperature discloses a single perovskite phase with a cubic symmetry. Dielectric measurements were carried out in the ranges (80-445 K) and (10(2)-10(6) Hz) of temperature and frequencies respectively. The ceramics exhibited normal and/or relaxor ferroelectric properties then some of them have very interesting dielectric characteristics in the vicinity of room temperature. A wide dielectric anomaly combined to the dielectric maxima shift toward a higher temperature with increasing frequency denotes either a diffuse phase transition or relaxor behavior in some ceramics. For any erbium concentration, when titanium is substituted by zirconium, the temperature of the permittivity maximum T-C (T-m) and the maximum permittivity (epsilon'(rmax)) decreases while Delta T-m(f)= [T-m(10(6) Hz) - T-m(10(2) Hz)] and tan delta increase. The diffuse phase transition parameters were calculated from the modified Curie-Weiss law linear fit. Further a relaxor nature was confirmed and endorsed by a good fit to the Vogel-Fulcher relation.