A paracrystalline array of defect clusters was shown to form in Zr-doped Co 3−δ O 4 spinel in the ZrO 2 /Co 1−x O composites while prepared by a sintering route at 1650• C in air. Analytical electron microscopic observations indicated the spinel precipitate and its paracrystal predominantly formed at the ZrO 2 /Co 1−x O interface and the cleavages/dislocations of the Co 1−x O host. Defect chemistry consideration suggests the paracrystal is due to the assembly of charge-and volume-compensating defects of the 4:1 type with four octahedral vacant sites surrounding one Co 3+ -filled tetrahedral interstitial site. The interspacing of such defect clusters is 4.9 times the lattice spacing of the average spinel structure of Zr-doped Co 3−δ O 4 . This spacing between defect clusters is about 0.98 times that of our previously studied undoped Co 3−δ O 4 . There is much larger (3.4 times difference) paracrystalline spacing for Zr-doped Co 3−δ O 4 than its parent phase of Zr-doped Co 1−x O.

No abstract

No abstract

No abstract

No abstract