Numerical Determination of the Local Ordering of PbMg1/3Nb2/3O3 (PMN) from High Resolution Electron Microscopy Images

Cation arrangement in the complex perovskites and vibrational spectra

“…The existence of such clusters of about 2 nm in diameter, spread regularly inside the crystal, has recently been conÐrmed by direct analysis of the highresolution electron microscopy images from PMN. 15 Unlike PST and PMN, the Raman spectrum of NBT does not show any mode in the wavenumber range considered above [ Fig. 1(a)].…”

“…In spite of the 1 : 2 composition of the B@ and BA ions in PMN, the principal features of vibrational spectra are mostly consistent with the 1 : 1 nanoclusters whose existence has recently been conÐrmed by direct electron microscopic observation. 15 The di †er-ence in the vibrational spectra is the basis of the present analysis. Comparison of the vibrational spectra with direct structural studies emphasizes the primary role of cation ordering in complex perovskites, in contrast to the conclusions of the initial analysis persisting with an overwhelming e †ect of disordering.…”

Damped soft phonons and diffuse scattering in40%Pb(Mg1∕3Nb2∕3)O3Stock1, Ellis2, Swainson3 et al. 2006Phys. Rev. B703551View full textAdd to dashboardCite

“…32 High resolution electron microscopy and polarized Raman studies have also provided strong direct evidence for short-range ordering on the B site. 33,34 It is interesting to note that near ͑100͒, the diffuse scattering peaks at around 1 / 3 where in pure PMN it is observed to peak at around the incommensurate position of ϳ0.1. The peak at around 1 / 3 is expected in a fully ordered Pb͑B 1/3 Ј B 2/3 Љ ͒O 3 with a BЈ-BЉ-BЉ-BЈ type structure providing evidence that the hightemperature diffuse scattering is associated with ordering on the B site.…”

Stress-modulated relaxor-to-ferroelectric transition in lead-free(Na1/2Bi1/2Schader1, Wang2, Hinterstein3 et al. 2016Phys. Rev. B885462View full textAdd to dashboardCite

“…Diffraction and optic index of refraction studies, however, have observed correlated clusters appearing below approximately 600 K in polycrystalline Pb(Mg 1/3 Nb 2/3 )O 3 [33,34] and (Pb 1-3x/2 La x )(Zr y Ti 1-y )O 3 [35]. Additionally, high-resolution optical microscopy investigations of Pb(Mg 1/3 Nb 2/3 )O 3 have indicated the existence of ordered nonstoichiometric regions, consisting of Mg 2+ and Nb 5+ cations on the B site, which are surrounded by a Nb-rich matrix [36]. Following investigations, however, revealed that thermal annealing can lead to domain coarsening, which cannot be explained by the space-charge model [37].…”