Dimer self-organization of 53Cr impurity ions in synthetic forsterite

摘要

Paramagnetic centers formed by isotopically pure impurity 53Cr ions in synthetic forsterite (Mg2SiO4) are studied by continuous wave electron paramagnetic resonance. It is shown that chromium ions substitute magnesium ions as single ion with nonlocal charge compensation and dimer associate formed by two closely spaced Cr3+ ions. It is found that the integral intensity of resonance transitions belonging to the dimer associates is much higher than that to be expected for the statistical distribution of the impurity Cr3+ ions in the forsterite host. Therefore, there is a mechanism favoring the self-organization of the Cr3+ ions in dimer associates during the crystal growth.