ELASTIC STABILITY OF HIGH-DOSE NEUTRON-IRRADIATED SPINEL

Elastic constants (C-11, C-12 and C-44) of spinel (MgAl2O4) single crystals irradiated to very high neutron fluences have been measured by an ultrasonic technique. Although results of a neutron diffraction study show that cation occupation sites are significantly changed in the irradiated samples, no measurable differences occurred in their elastic properties. In order to understand such behavior, the elastic properties of a variety of materials with either normal or inverse spinel structures were studied. These results show that the cation valence and cation distribution appear to have little influence on the elastic properties of spinel materials.