Inhibition of Positronium Formation in Yttria Stabilized Zirconia Nanopowders Modified by Addition of Chromia
2013
Abstract
The effect of chromia additive on defects in yttria stabilized zirconia (YSZ) nanopowders was investigated in this work. It was found that positrons are trapped at vacancy-like misfit defects at grain boundaries and at larger defects situated at triple points.
Moreover, a long-lived ortho-positronium contribution was found in YSZ nanopowder without chromia. Addition of chromia prolongs the lifetime of positrons trapped at vacancy-like misfit defects which indicates segregation of Cr ions at grain interfaces and interaction of Cr with vacancy-like misfit defects.
Furthermore, addition of chromia completely suppresses formation of positronium.