Impedance spectroscopy of Mg-partially stabilized zirconia and cubic phase decomposition

Electrical conductivity measurements were carried out by impedance spectroscopy on nominally pure and magnesia-doped zirconia in the 3-13.7 mol% concentration range. In the partial-stabilization field, the impedance diagram show the characteristic grain and grain boundary semicircles, as well as an extra are at intermediate frequencies. This extra arc is interpreted as a characteristic of partial blocking of electrolyte conduction by the monoclinic grains. As usual, the resistances associated with the blocking processes exhibit activation energies slightly higher than the bulk resistance. All these activation energies increase with the MgO content. The cubic phase decomposition can easily and accurately be monitored by impedance spectroscopy.