Effect of Fe-doping on the structure and magnetoelectric properties of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 synthesized by a chemical route

Abstract

B-site Fe-doped (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1)O₃ was synthesized by a facile chemical route to study the effect of doping on its physical properties. Detailed analysis of X-ray diffraction and Raman spectroscopy data revealed an increased lattice strain and thereby deviation from the morphotropic phase boundary with the progressive doping of Fe from 1 to 5 mol%. Such structural changes have resulted in the weakening of the energy band gap as well as deterioration of the ferroelectric polar nature which was evidenced by a shift of tetragonal to cubic transitions towards room temperature and hard doping effects in ferroelectric hysteresis. The doped samples exhibited room temperature ferromagnetism. Combined Mossbauer and X-ray photoelectron spectroscopic studies suggest that oxygen vacancies and defect complexes induced by Fe doping play a major role in magnetic properties. Local piezoresponse measurements illustrated imprint characteristics of ferroelectric domains in undoped and doped samples at the nanoscale. Room temperature magnetoelectric (ME) measurements revealed that 1 mol% Fe doped sample, having higher ferroelectric polarization and moderate magnetization, exhibits a strong ME response with a coefficient of 12.8 mV cm⁻¹ Oe⁻¹. The present study on Fe-doping effects on the structure and related ME properties of this important lead-free material is useful to tailor multiferroic applications in electronics.