Current-Voltage Characteristics of Semiconducting Barium Titanate Ceramic

Abstract

The current-voltage characteristics of semiconducting BaTiO3 ceramic have been investigated with electric fields up to 2×104 V/cm. The results obtained are in agreement with Heywang's model for conduction in this material (other published models being unsatisfactory) provided that allowance is made for the Ohmic drop in the bulk material. It is found that most of the current is channeled through small pores (0.1–0.5 μ diam) in the intergranular boundaries.

Low Temperature Radio-Frequency-Sputtered (Ba, Sr)TiO[sub 3] Films on Pt/TiN/Ti/Si Substrates with Various Oxygen/Argon Mixing Ratios

“…[24][25][26] Third, a BST film, with a narrow bandgap of 3.2-4.0 eV, can normally be considered as semi-insulator or semiconductor, so the grain boundary scattering suppresses the current. [27][28][29] The reduced grain size with higher OMR forms more grain boundaries to decrease the leakage current. Hence, BST films deposited in higher OMR ambient exhibit compensation of oxygen vacancies, smoother interfaces and smaller grains, all of which reflect the decrease of the leakage current.…”

Current-voltage characteristics of donor-doped BaTiO3semiconducting ceramics

“…Earlier work by Mallik and Emtage (1968) showed that, while at intermediate voltages I was proportional to V:, with n between 1.5 and 3, the I-V behaviour again became ohmic when V, was increased above 2 V (as calculated from their results). Using diffusion theory these authors were able to explain their results in terms of the Heywang model, provided that the ohmic drop in the bulk material was taken into account.…”

“…In his original model, Heywang assumed a thermionic emission type of conduction over the potential barriers. On the other hand, workers such as Mallik and Emtage (1968), Ihrig and Puschert (1977) and Kulwicki and Purdes (1970) considered diffusion as a more likely process for current transport. Doubts about the thermionic emission process have been expressed more recently by Mader et a1 (1987), on the 0022-37271891091 393 + 05 $02.50 @ 1989 IOP Publishing Ltd basis that the electron mean free path in these materials is much smaller than the thickness of the depletion layer.…”

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

“…4 Failure to observe exponential j(V) dependence has prompted a search for alternative models. By taking into account the low mobility of electrons in BaTiO 3 , Mallick and Emtage, 5 and later Kulwicki and Purdes 6 suggested diffusion current through the grain boundary ͑GB͒ as an explanation of j(V). Space charge limited current ͑SCLC͒ in PTCR BaTiO 3 was reported by MacChesney and Potter 7 and later by Nemoto and Oda.…”