Annealing effects on the structural, thermal, and electrical properties of 10PbTiO_3-10Fe_2O_3-30V_2O_5-50B_2O_3 glass

摘要

Glasses containing lead titanate (PbTiO_3) have recently attracted much attention due to its unique electrical properties at high temperature. However, its large lattice anisotropy makes its sinterability difficult. 10PbTiO_3-10Fe_2O_3-30V_2O_5-50B_2O_3 glass was prepared by conventional fast quenching technique. The estimated crystallite size after annealing at 773 K for 20 h was 62.6 nm. After annealing, triclinic iron vanadium oxide and monoclinic lead vanadium oxide phases were partially formed. The crystallization temperature (T_c) at different heating rates (β) has been investigated using Kissinger and Ozawa models under non-isothermal mode. The values of various kinetic parameters such as activation energy of crystallization (E_c), rate of crystallization (K_p), Avrami index (n), thermal stability (S), and Hruby number (H_r) have been calculated. The presence of Fe_2O_3 and PbTiO_3 in the glass after annealing was found to enhance its thermal stability and electrical conductivity. The electrical conductivities of as-quenched and annealed glass were evaluated by dc conductivity. The dc conductivity was discussed in terms of small polaron hopping (SPH) mechanism.