Relaxations in Ba2BiSbO6 double complex perovskite ceramics

Abstract

The electric properties of the complex double perovskite Ba 2 BiSbO 6 have been investigated using impedance spectroscopy in the frequency range from 1 Hz up to 1 MHz and in the temperature range from room temperature up to 560 K. There are two contributions to the electrical properties due to the grain and grain boundary. The oxygen vacancies play an important role in the conductivity and strongly increase the dielectric constant at high temperatures. The analysis of the frequency dependence of the conductivity clearly shows the structural phase transition of this compound near 515 K.

Electrical properties and scaling behaviour of rare earth based Ho2CoZrO6 double perovskite ceramics

“…charge carriers are the same in HCZ, which may be interpreted as polaron hopping between neighbouring sites within the crystal lattice. The activation energy for the relaxation associated with the bulk is substantially lower than that observed in some other double perovskites, such as Ba 2 AlNbO 6 (0.49 eV) [45], Ca 2 FeSbO 6 (0.60 eV) [46], Ba 2 FeSbO 6 (0.75 eV) [47] and Ba 2 BiSbO 6 (1.14 eV) [5]. This bulk activation energy has a magnitude of the order of oxygen vacancy motion [48].…”

“…The double perovskite oxides with general formula A 2 B 0 B 00 O 6 have attracted a great deal of attention due to their scientific as well as technological importance [1][2][3][4][5][6][7]. Double perovskites have shown promise in the development of spin polarized conduction and ferromagnetic semiconductors.…”

“…Various interesting properties of double perovskites e.g. thermal properties in Sr 2 FeMoO 6 [12], structural, transport, magnetic and optical properties in A 2 CrWO 6 (A = Sr, Ba and Ca) [1], grain and grain boundary study in Ba 2 FeNbO 6 [13], Ba 2 BiSbO 6 [14] have been reported, besides them the investigation of electrical properties of double perovskite ceramics have been tremendous research interest in recent years [13][14][15][16][17][18][19]. Since most of the devices are operated in the ac electrical mode, the investigation of ac electrical conduction of these materials has been the focus of researchers in recent years.…”

Low-temperature dielectric properties of double-perovskite Ca2CoNbO6

“…Two sets of relaxations were frequently reported in different type of materials including double peroskite, and were always ascribed to the contributions from grain and grain boundary [13][14][15][16][17][18][19][20]24]. The impedance spectrum is extremely advantageous for distinguishing grain and grain boundary contributions [25].…”

“…The results reported by Castro et al. revealed that Ba 2 BiSbO 6 show multi-relaxations [13]. Lin et al reported a relaxor-like dielectric behavior in La 2 NiMnO 6 [14] and La 2 CoMnO 6 [15].…”