The I-V characteristics and impedance of a single grain boundary in sintered (1570C, air) specimens of Nb-doped material were investigated. A micro-electrode method was used to measure the I-V characteristics, and the impedance, of a single grain-to-grain junction. The single grain boundary was shown to exhibit a non-ohmic behavior, and the breakdown voltage was about 7V. It was observed that the capacitance of the grain boundary increased, and the resistance decreased, with increasing Nb content.

I-V Characteristics and Impedance Spectroscopy of a Single Grain Boundary in Nb-Doped SrTiO3. S.H.Kim, H.T.Kim, J.H.Park, Y.Kim: Materials Research Bulletin, 1999, 34[3], 415-23