Quadrupole frequency measurements using defect associated electric field gradients in cubic host materials

Abstract Level Mixing Spectroscopy (LEMS) can be used to determine nuclear quadrupole moments. In this paper it is shown how LEMS can be applied to nuclei implanted in a cubic lattice. In this case the quadrupole interaction is due to electric field gradients produced by defects. The method has been illustrated by measuring quadrupole moments of 202–204 Po isomers produced in nat Pt( 12 C, 4n) and nat Pt( 13 C, 5n) reactions, the (natural) Platinum serving as a host material. The result could be analysed with the assumption of two different defect associated sites, making up for about 80% of the total site population. The experimental ratio Q ( 202 Po,8 + )/ Q ( 204 Po,8 + ) is in agreement with the systematics in the lead region. LEMS measurements in cubic crystals provide another nuclear method for the study of nuclear quantities or solid state parameters.