Dielectric relaxation in perovskite Ba(Zn1/2W1/2)O3

Synthesis and characterization of ZnWO4 ceramic powder

“…6 shows a room temperature representative plot. Under the pure monodispersive Debye process, semicircular plots are expected with a centre located on the e 0 axis whereas, for polydispersive relaxation, these Argand plane plots are close to circular arcs with end points on the axis of real's and a centre below this axis [16]. The Cole-Cole plot confirms the polydispersive nature of dielectric relaxation of ZnWO 4 ceramic powder.…”

“…Fig. 5(b) shows the variation of dielectric loss (e 00 ) of ZnWO 4 ceramic powder with the change of frequency at the room temperature and it is observed that the value of tan d was found to increase up to a particular frequency, beyond that it decreases thus revealing the dielectric relaxation phenomena of ZnWO 4 ceramic powder [16]. In the dielectric materials, defects, space charge formation, lattice distortions, etc., in the boundaries could produce absorption current resulting in a loss factor (tan d) and with high alternating frequency these could follow the field applied and then gradually come down to a low value [15].…”

Relaxations in Ba2BiSbO6 double complex perovskite ceramics

“…These two relaxation processes are due to the bulk ͑first process͒ and to the grain boundary ͑second process͒. This effect was not observed in other double perovskites, [39][40][41][42][43][44][45] probably due to the high sintering temperature used in these other compounds. In order to analyze the temperature dependence of the relaxation time of these two processes we plot in Fig.…”

“…This effect is not observed in other double perovskites. [39][40][41][42][43][44][45] As well as in other double perovskites, the frequency at which the maximum occurs depends on the temperature where the relaxation time is thermally activated. At the right of the main peak a subtle peak whose maxima shift up with the temperature is observed.…”

High‐Temperature Decomposition of B‐Site‐Ordered Perovskite Ba(Zn1/2W1/2)O3

“…Khalyavin et al , 9 on the other hand, measured a Q × f of 22 000 GHz, albeit with the presence of secondary phases in the ceramics. To complicate matters further, in a recently published paper, Prakash et al 10 claim that the crystal structure of Ba(Zn 1/2 W 1/2 )O 3 synthesized by solid‐state reaction is monoclinic, while in all the other literature reports, Ba(Zn 1/2 W 1/2 )O 3 belongs to the Fm ‐3 m space group with cubic symmetry. With these inconsistencies in mind, we decided to perform a detailed investigation of the crystal structure and chemistry of Ba(Zn 1/2 W 1/2 )O 3 .…”