ELECTRON-PARAMAGNETIC RESONANCE OF CU2+ IN KHCO3 CRYSTALS

Electron paramagnetic resonance study of the Cu2+ doped into KHCO3 single crystals has revealed that it is of axial symmetry. The g-values of Cu2+ are very nearly identical to some known Cu2+ in square-planar coordinations. The resonance linewidth is relatively narrow, such that the hyperfine patterns of Cu-63 and Cu-65 can be resolved. Moreover, the observation of the forbidden transitions induced by the Cu nuclear electric quadrupole interaction permits a test of the usual hypothesis that the g-factor, the hyperfine interaction, and the nuclear electric quadrupole interaction share a common set of principal axes.