The electronic properties of complex oxides of bismuth with the mullite structure

Structure and some magnetic properties of (BiFeO3) x -(BaTiO3)1−x solid solutions prepared by solid-state sintering

“…The hyperfi ne interaction parameters of the quadrupolar component for 0.9BiFeO 3 --0.1BaTiO 3 and 0.8BiFeO 3 -0.2BaTiO 3 solid solutions are as follows: the isomer shift  = 0.26 mm· s 1 and the quadrupole splitting  = 0.52÷0.74 mm·s 1 (in dependence on the composition and sintering temperature). In these two cases the doublet may be attributed to the paramagnetic Bi 2 Fe 4 O 9 impurity phase, the obtained hyperfi ne interactions parameters are in good agreement with the literature data [8]. In the case of 0.7BiFeO 3 -0.3BaTiO 3 solid solu- tion, the doublet with parameters  = 0.35 mm·s…”

Hyperfine interactions in some Aurivillius Bi+1Ti3Fe−3O3+3 compounds

“…about 0.40 mm s À1 , to iron ions in octahedral sites. This assignment may be confirmed by a fact that generally the isomer shift originated from octahedrally coordinated iron ions Fe 2+ is greater than that from tetrahedral Fe 3+ ions [21,24,25]. The most visible changes are observed in area ratio, which can be roughly regarded as the occupancy of various sublattices.…”

Phase equilibria investigations and thermodynamic modeling of the system Bi2O3–Al2O3

“…Besides, the compound presents a remarkable ionic conductivity due to the presence of vacancies in oxygen lattice as it was evidenced by Abrahams et al [22]. Later, the compound was synthesized either in monocrystal form by Burianek et al [23], or by powder sintering by MacKenzie et al [24]. They measured the peritectic melting at 1084°C (by DTA) and 1050°C (by TGA/DSC in air at 10°C min À1 ) respectively.…”

“…He was also interested in the effect of oxides additions such as Al 2 O 3 and Fe 2 O 3 on the stability of the bcc-c form of Bi 2 O 3 . Thus, he established the existence of a new compound identified as Bi 24 Al 2 O 40 which is out of the Bi 2 O 3 -Al 2 O 3 pseudo-binary system. In 1964, Levin and Roth worked on the formation of bcc phases isomorphous to c-Bi 2 O 3 in thirty-three Bi 2 O 3 -M x O y systems including Bi 2 O 3 -Al 2 O 3 .…”