DIFFUSE NEUTRON-SCATTERING OF IRON-DOPED NICKEL-OXIDE

We have investigated the equilibrium defect structure of single crysta lline nonstoichiometric iron doped nickel oxide, (Ni1-xFex)(1-delta)O (x=0.06), at high temperatures (1000-1250 degrees C) and nonstoichiome tries 0.004<delta<0.030 by diffuse elastic neutron scattering. The obs erved characteristic diffuse intensity around G(200) can be explained by tetrahedrally coordinated iron-interstitials surrounded by four cat ion vacancies and their displacement fields. A similar pattern of the diffuse scattering was found in our previous study of wustite, Fe1-del taO (delta=0.054), indicating that Fe-doped nickel oxide may be regard ed as ''diluted wustite''.