Dielectric and a.c. conductivity studies in pure and manganese doped layered K2Ti4O9 ceramics

A.C. Conductivity Investigations on Layered Na2-x-yLixKyTiSingh1, Shripal2 2013Journal of Materials0000View full textAdd to dashboardCite

“…This is due to electron hopping through Ti-Ti chains of (Ti 3 O 7 ) 2− two-dimensional layers and alkali ion hopping process occurring through alkali ion sites in interlayer space existing between the opposite (Ti 3 O 7 ) 2− layers, respectively. The ionic conductivity involves associated interlayer ionic conduction, unassociated interlayer ionic conduction, and modified interlayer ionic conduction as proposed earlier [36], whichever occurs and dominates over this region and in the next higher temperature regions. In addition, such a contribution includes the role of different dipoles as discussed by Shripal et al [28] in a very recent communication and is responsible for giving a trend of variations in tan and permittivity ( ) values with temperature and frequency.…”

“…It is also observed that frequency dependence persists up to this higher temperature region as well. However, I-V dipoles present in the interlayer space break up completely up to the upper limit of previous region II, and the mechanism of conduction can now be proposed as "unassociated interlayer ionic conduction" for SLPT-1 and SLPT-2 materials as proposed [36]. So, the two mechanisms involve unassociated interlayer ionic conduction with alkali ion hopping and operate for SLPT-1 and SLPT-2 compositions.…”

Dielectric–spectroscopic and AC conductivity studies in iron doped layered Na2Ti3O7 ceramics

“…DC conductivity and EPR investigation in iron doped layered Na 2 Ti 3 O 7 have been reported by Shripal and coworkers [23]. Very recently, dielectric-spectroscopic and AC conductivity studies have been reported on layered N 2−x K x Ti 3 O 7 (x = 0.2, 0.3, 0.4) and on pure and manganese doped layered K 2 Ti 4 O 9 ceramics [24,25].…”

The crystal structure of Rb2Ti2O5

“…The ternary titanium oxides denoted by M 2 Ti n O 2nþ1 with M = Li, Na, K, Rb, Cs, Fr, called the Andersson-Wadsley type alkali titanates (Tournoux et al, 1986), with layered structure for 2 n 5 and tunnel structure for 6 n 8, are known for their interesting properties (Shripal et al, 2005). In particular, some of them present ferroelectric phase transitions, with remarkably high Curie temperatures (Vikram et al, 2010).…”