Electron low energy-loss functions of Pb(Mg1/3Nb2/3)O3: Theory and experiment

Abstract

Articles you may be interested inElectronic transitions and dielectric functions of relaxor ferroelectric Pb(In1∕2Nb1∕2)O3-Pb(Mg1∕3Nb2∕3)O3-PbTiO3 single crystals: Temperature dependent spectroscopic study Appl. Phys. Lett.Electronic structure studies of undoped and nitrogen-doped tetrahedral amorphous carbon using high-resolution electron energy-loss spectroscopy Transmission electron energy-loss spectroscopy measurements of the dielectric function of Si/SiO 2 multilayers Local low energy-loss functions ͑ELFs͒ of chemical ordered nanodomains in relaxor Pb͑Mg 1/3 Nb 2/3 ͒O 3 ͑PMN͒ were obtained by using Kramers-Krönig analysis of experimental electron low energy-loss spectra. Electronic structures and dielectric functions were calculated via ab initio calculation using the full-potential linearized augmented plane-wave method on a 30 atom PMN supercell with B-site cation ordering along the ͓111͔ direction. The theoretical ELFs are fundamentally in agreement with the experimental ELFs. Furthermore, we systematically elucidate all the peaks in the low ELF based on the ab initio calculated densities of states. It is found that the Nb 4d -O 2p hybridization is enhanced through ferroelectric transition, which makes the O 2p collective excitation energy upper shift in ELF, while Mg, also as the B-site ion, presents no covalent bonding effect with O.

Why Sn doping significantly enhances the dielectric properties of Ba(Ti1-xSnx)O3

“…Therefore, in parts of the matrix in which the concentration of Sn atoms is sufficiently high, the continuous dipole-dipole interaction is destroyed, and the long-range Coulomb potential cannot be built up in the matrix, as demonstrated in Figure 3(c). Therefore, the normal ferroelectric domain cannot form; this effect is similar to the phenomenon associated with Mg atoms in Pb(Nb 2/3 Mg 1/3 )O 3 19. However, the valance of Sn is equal to that of Ti.…”

Static and dynamic polar nanoregions in relaxor ferroelectric Ba(Ti1−xSnx)O3Xie1, Li2, Yu3 et al. 2012Phys. Rev. B782260View full textAdd to dashboardCite

“…11,12 The polar nanoregions can either result from structural disorder or chemical disorder. For lead-based relaxors, it was suggested that the chemically ordered regions [13][14][15][16] or the random distribution of B-site atoms [17][18][19] constitute the necessary condition for the appearance of polar nanoregions. The chemically ordered regions either act as sites to localize the polar nano-regions (PNRS) in a dynamic way 16 or as sites to pin the PNRs in a static way.…”