Microstructural, Electrical, and Magnetic Properties of Acceptor‐Doped Nanostructured Lead Zirconate Titanate

Abstract

The changes in the ferroelectric and magnetic properties of the nanostructured Pb(Zr0.52Ti0.48)1‐xFexO3 (0 ≤ x ≤ 0.06) due to the doping of different amounts of acceptor ions (Fe3+) have been studied. X‐ray diffraction studies show that the system maintains the tetragonal phase up to the doping of 2 mol% of Fe3+ and the formation of secondary phase magnetoplumbite (PbFe12O19) on further doping. Electron paramagnetic resonance studies have revealed the formation of defect centers which in turn arise due to the interaction of Fe3+ ions with oxygen vacancies, which are generated in the lattice. This results in the appearance of room temperature ferromagnetic (RTFM) behavior in the doped samples. The dielectric studies reveal that with the concentration of Fe3+ the peak near the maxima of dielectric constant (ε′m) is broadened. Studies of the defect dipoles on the ferroelectric properties have been performed by polarization measurement. The variations of the above properties with the structural and morphological features of the samples have also discussed.

Multifunctional behavior of acceptor-cation substitution at higher doping concentration in PZT ceramics

“…The crystallite size for PZTF ceramic compositions was calculated using the Debye-Scherrer equation 3[41]: , which also decreased with increase in Fe-doping. A similar trend has been reported by others also [15,38,42]. This is reflected in the observed shift in XRD peaks to higher 2θ, Fig.…”

“…constant as the substitution with Fe 3+ compresses the Ti-O bond distance henceforth intensifying the Ti-O bond interaction and reducing the cell size which is in accordance with the XRD results. [2,15,19,24,38,39,43]. This decrease in the RT value of dielectric constant with increase in Fe-doping in PZT ceramics has also been reported in other literatures, Fig.…”

“…suggest the restraining effect of Fe 3+ ions on grain growth caused by their lower mobility due to the larger ionic radius and atomic weight in comparison to Ti 4+ ions. Also, the grain boundary motion is restricted by the accumulation of Fe 3+ and secondary magneto-plumbite phase at the grain boundary resulting in reduced grain growth [15,39,43]. This decrease in grain size with increase in doping concentration has also been reported in earlier literatures as can be seen in Table. 1 and inset of Fig.…”

“…which is likely to occur when a large ion such as Fe 3+ (0.645 Å) substitutes a smaller ion like Ti 4+ (0.605 Å). The subsequent reduction in the c/a ratio signifies repression of ferroelectric distortion [15,[38][39][40]. Fig.…”

“…‫ݎ(‬ ே ఱశ = 0.78 Å), Sb 5+ ‫ݎ(‬ ௌ ఱశ = 0.60 Å) owing to their probable ionic radii [15][16][17][18][19]. The addition of Fe 3+ to PZT ceramics is of particular interest as it shows varied effects depending on the content of doping or solubility limit in PZT.…”