Chemical disorder and 207 Pb hyperfine fields in the magnetoelectric multiferroic Pb (F e 1 /2 S b 1 /2 ) O 3 and its solid solution with Pb (F e 1 /2 N b 1 /2 ) O 3

摘要: We report on the results of magnetic susceptibility, electron paramagnetic resonance, and $^{207}\mathrm{Pb}$ nuclear resonance (NMR) studies magnetoelectric multiferroic $\mathrm{Pb}(\mathrm{F}{\mathrm{e}}_{1/2}\mathrm{S}{\mathrm{b}}_{1/2}){\mathrm{O}}_{3}$ (PFS) ceramic, as well its solid solution with $\mathrm{Pb}(\mathrm{F}{\mathrm{e}}_{1/2}\mathrm{N}{\mathrm{b}}_{1/2}){\mathrm{O}}_{3}$ (PFN) different degrees 1:1 ordering $\mathrm{F}{\mathrm{e}}^{3+}$ nonmagnetic $\mathrm{S}{\mathrm{b}}^{5+}$ ions. The has been studied by x-ray diffraction (XRD) NMR methods. In particular, two spectral lines, originating from ordered disordered regions, respectively, are resolved in spectra. This demonstrates presence spatially heterogeneous where regions embedded into a matrix. Combining XRD data, we have determined both long-range order parameter $s$ volume fraction ${s}^{\ensuremath{'}}$ for all investigated samples. values vary range $s=0\ensuremath{-}0.93$ ${s}^{\ensuremath{'}}=0\ensuremath{-}1$. found that Fermi contact interaction strongly depends disorder Fe/Sb positions: whereas it reaches 7.08 MHz lattice, is almost zero environment. These further supported PFS-PFN solutions. analysis experimental data terms density functional theory reveals noticeably higher hybridization between Pb 6s Fe 3d orbitals case. ions strong impact properties PFS, leading to transformation antiferromagnetic phase chemically samples spin glass state already partially $(s=0.35)$ specimens. our opinion, difference PFN PFS related fact completely disordered, contrast which only small existing matrix prevent percolation nearest-neighbor Fe\ensuremath{-}Fe exchange across lattice.