ELASTIC STABILITY OF HIGH-DOSE NEUTRON-IRRADIATED SPINEL

Elastic constants (C-11, C-12 and C-44) of spinel (MgAl2O4) single cry stals irradiated to very high neutron fluences have been measured by a n ultrasonic technique. Although results of a neutron diffraction stud y show that cation occupation sites are significantly changed in the i rradiated samples, no measurable differences occurred in their elastic properties. In order to understand such behavior, the elastic propert ies of a variety of materials with either normal or inverse spinel str uctures were studied. These results show that the cation valence and c ation distribution appear to have little influence on the elastic prop erties of spinel materials.