Studies of Ferroelectric and Magnetic Phase Transitions in Pb_1−xA_xFe_1/2Nb_1/2O₃(A-Ca, Ba) Solid Solutions

Abstract

Dielectric and Mossbauer studies of Pb1-xAxFe1/2Nb1/2O3 (A- Ba, Ca) ceramic compositions show that the Néel temperature in these solid solutions drops down at x ≈ 0.15–0.20. At the same threshold the polarization also loses its long-range order and compositions with x > 0.1 exhibit relaxor behavior. The data obtained suggests that there exists a Pb-mediated superexchange controlling the long-range antiferromagnetic order. Thus, studied multifunctional solid solutions demonstrate the possibility of controlling the magnetic and ferroelectric properties simultaneously by changing the concentration of nonmagnetic lead cations only.