Electrical properties of polycrystalline PTCR barium titanate

A phenomenological model of conduction in Ho-doped barium titanate sensor

“…These compares favorably with values reported elsewhere [19]. On the basis of the Heywang's theory, the resistivity of the grain boundary depends exponentially on the potential barrier [7,19,21], and is given by: Fig. 4.…”

“…The measured relative permittivity at any temperature T, above the Curie temperature T C , follows modified the Curie-Weiss law [19],…”

“…Barium titanate doped with different molar fractions of Ho 2 O 3 has been studied by many workers [14][15][16][17][18][19]. It has been mentioned earlier that barium titanate doped with holmium concentration of 0.3 mol% exhibits maximum conductivity at room temperature [15].…”

Influence of Nb 5+ and Sb 3+ dopants on the defect profile, PTCR effect and GBBL characteristics of BaTiO 3 ceramics

“…4). On the other hand, highly-doped BaTiO 3 ceramics (P3 and P6) are yellow in colour and exhibit an extremely high resistivity (%10 13 .cm) at room temperature, with a NTCR effect as the temperature raises (Fig. 3).…”

“…In addition to it, dopant segregation and vacancies formation pin grain boundaries mobility during sintering, inhibiting grain growth. As the effective electrical resistivity for PTCR-BaTiO 3 also depends on the density of grain boundaries in the total sample, 12,13 The effective conductivity of the materials with a fine-grained matrix (P2, P3, P5, P6) is strongly reduced.…”