Manifestation of strong magnetic and giant Raman anisotropy in single crystals of Cu for H substituted strontium hydroxyapatite

Single crystals of Cu-doped strontium apatite containing the linear chromophore group [OCuO]− exhibit high easy-c-axis magnetic anisotropy with an Seff = 1/2 and geff = 4 ground doublet, and show an extremely anisotropic resonance Raman effect of the OCuO symmetric stretching vibration. The latter combines with adjacent vibration modes and is associated with an electron transfer to the first exited state thus allowing the magnetic anisotropy to be spectroscopically probed.