Electrical properties and scaling behaviour of Sm3 +  doped CaF2-bismuth borate glasses

Abstract

The electrical properties for 20Bi 2 O 3 -60B 2 O 3 (20−x)-CaF 2 -xSm 2 O 3 glasses (0 ≤ x ≤ 2) were measured in the temperature range 297 K up to 629 K and in the frequency range 0·1-100 kHz. The d.c. and a.c. conductivity values and the dielectric loss (tan δ) values were found to increase with increasing Sm 2 O 3 content, whereas the activation energy of conductivities and the dielectric constant decreased. These results were attributed to the introduction of the rare earth ions; promote the formation of a high number of non-bridging oxygen atoms, which facilitate the mobility of charge carriers. The frequency dependence of the a.c. conductivity follows the power law σ ac (ω) = Aω s . The frequency exponent (s) values (0·64 < s < 0·8) decrease with increasing temperature. This suggested that the a.c. conduction mechanism follows the correlated barrier hopping model (CBH). The dielectric constant (ε ) and dielectric loss (tan δ values) were found to increase with increasing temperature and increasing Sm 2 O 3 concentration in the glass. The a.c. conductivities as a function of frequency at different temperatures of a given glass superimposed onto a master curve (Roling scaling model). Furthermore, we have performed to scale the data as a function of composition. Two master curves were obtained, which suggested that there are differences in dominant charge carriers between glasses having Sm 2 O 3 concentration ≥1 and glass of Sm 2 O 3 concentration <1.

Temperature dependent electrical transport characteristics of BaTiO3 modified lithium borate glasses

“…At lower frequency the charge carriers may easily hop out of the low energy sites and thus accumulate at high energy barrier sites. 18,19 This results in an increased net polarization and hence leads to an increased dielectric constant and loss. However, at high frequency, the electric field changes so fast that the oscillations of charge carriers tend to lag behind the applied electric field.…”

Ionic Conductivity and Dielectric Relaxations in Li+ Ions Doped Zinc Borate Glass System

“…And hence reduction in the polarization (due to the departure of charge, massing up at the free energy barrier) and reduction in the values of dielectric parameters. [47][48][49][50][51] At low frequencies, all the polarization mechanisms are active. Still, as the frequency increases to the higher value, polarization decreases because dipoles do not fit in with the varying external field, resulting in the reduction of dielectric relaxation parameters.…”

Designing Glass Nanocomposites with Nonbridging Oxygen Defects: An Approach to Improve Sodium-Ion Conduction

“…Sodium manganese oxide as a high-performance cathode was designed utilizing the complementary effects of inert Ti 4+ ions and active Ni 2+ ions . It has been reported that incorporation of rare-earth elements as network modifiers leads to the generation of more nonbridging oxygen (NBO) atoms in the glass network. − This is an effective approach for achieving faster ion migration ensuring enhanced conductivity with reduced activation energy …”

“…38−40 This is an effective approach for achieving faster ion migration ensuring enhanced conductivity with reduced activation energy. 41 On the verge of miniaturization, the advent of nanoscale materials has provided several new developments in the field of next-generation batteries, 42,43 dielectric supercapacitors, 44−46 and magnetic sensors. 47−50 The reduced size in the nanomaterial scales down the ion diffusion length and accelerates ion transport.…”