Models of the current–voltage dependence of BaTiO3 with positive temperature coefficient of resistivity

Abstract

Current–voltage j(V) characteristics of barium titanate based positive temperature coefficient of resistivity thermistors were analyzed in terms of space charge limited current, trap-filled limited current, Frenkel–Poole, double-Schottky barrier, and small radii polaron models. It is shown that for the double-Schottky barrier model, the j(V) dependence does not obey the relation j∝exp (eV/2kT) at temperatures near or above the resistivity maximum. Instead, the j(V) characteristics show significant dependence on the interface charge. With increasing temperature, the region of nonlinear j(V) dependence is expected to shift towards higher voltages due to an increase in the equilibrium concentration of unoccupied interface states.

Non‐linear coefficient of BaTiO 3 ‐doped ZnO varistor

“…The PTCR is a non-linear variation of resistance with temperature depending on grain boundary resistive behaviour [8,9]. According to Heywang in [10], its current density in the paraelectric phase should obey the exponential dependence. BaTiO 3 as doping of ZnO-based varistor can influence the degree of non-linearity of conduction and enhance the thermoelectric performance of ZnO.…”

Characterisation of the R–T response of BaTiO3 thermistors on three different length scales

“…There are several published models describing the nature of the barrier structure in PTC thermistors. 22 Generally, different models predict different field dependences of resistance, and so fitting the field dependence is a good way to test the validity of these models. Although none of the data collected in this study fitted the predictions of any of the common models over an extended voltage range, when our R-T data was plotted as I versus V 2 , as a test for the space charge limited current (SCLC) model, a significant difference was observed between the strongly and weakly field dependent boundaries (Fig.…”

Effect of Sintering Atmosphere on Dielectric Properties of LaAlO3-SrTiO3System

“…7 is not conclusive evidence for the existence of small-radius polarons. The electrical conductivity from small polaron "hopping" is described by equation (8) in an adiabatic system [16].…”