Phase transition and conduction mechanism of rare earth based tungsten-bronze compounds

Tailoring of electrical properties of BiFeO3 by praseodymium

“…The magnitude of ε r increases with rise in temperature. The increase in the value of ε r can be ascribed as the electron-phonon interaction [12]. The increase in ε r can be understood in terms of the thermally activated transport property and presence of space charges [13].…”

Dielectric response and pyroelectric properties of lead-free ferroelectric Ba3(VO4)2

“…The decrease in the value of n on increasing temperature suggests an increase in interaction between the lattices and mobile ions and can be explained on the basis of dynamical theory. 37,39 As per this theory, one of the transverse optical modes (soft mode) gets weakened on increasing temperature and thereby, making the restoring force to decrease. As a result, the charge carriers, coupled with soft mode, become very mobile at this temperature and hence conductivity will also be increased.…”

“…38 The exponent n represents interaction between mobile ions with the lattice around them. 39 The plot reveals that the value of n decreases with temperature. The decrease in the value of n on increasing temperature suggests an increase in interaction between the lattices and mobile ions and can be explained on the basis of dynamical theory.…”

“…7) suggests that the material have relatively high voltage responsivity and detectivity as compared to some reported compounds. 39 This may be attributed to space charge effect or enhanced activity of thermally agitated intrinsic charge carriers.…”

Interdependence between electrical and magnetic properties of polycrystalline cobalt-substituted tungsten bronze multiferroic ceramics

“…Based on these extraordinary properties, these lead-free ferroelectric materials show a great promise in various electronic devices such as transducers, actuators, capacitors, ferroelectric random access memory (FERM) and microwave tunable device applications. [1][2][3][4][5] The TB-type structure [6][7][8][9] consists of a complex array of distorted BO 6 octahedral sharing corners in such a way that three different types of interstices (A, B and C) are available for cations' substitution in the general formula, where A 1 and A 2 sites are commonly filled by divalent or trivalent cations, B 1 and B 2 sites by tetravalent or pentavalent cations and C site being small, regularly remains vacant giving the general formula A 6 B 10 O 30 . It has been found that different ionic substitutions in the above-mentioned sites can play an important role in tailoring their physical and electrical properties.…”