STABILIZATION OF SUPEROXIDE AND CO3- RADICALS THROUGH CRYSTALLIZATION OF CACO3

Unstable superoxide radicals (g(a)=2.010, g(b)=2.064, g(c)=2.049, and g(d)=2.006) and CO3- hole centers (g(x)=2.017, g(y)=2.011, and g(z)=2.002) were stabilized in CaCO3 when the inorganic material was crystallized from radical solution. The radicals surrounded by the lattice give strong electron spin resonance (ESR) signals at room temperature. The signal intensities of superoxide and CO3- radicals generated in H2O2 solution and doped in CaCO3 are much stronger than those obtained by adsorption. The color of radical-doped CaCO3 is different from that of the radical-adsorbed one. On heating the samples, the spectrum and the color of the radical-doped CaCO3 powder changed. The effects of impurities on the spectrum of radical-doped inorganic materials are studied. Some doping experiments have been conducted using other inorganic materials.