A new mercury complex CH3NH3HgClBr2 was prepared with partial substitution of chlorine by bromine in the ferroelectric compound CH3NH3HgCl3. The complex has been characterized by different physico-chemical methods. X-ray studies of CH3NH3HgClBr2 showed an isomorphous character with the paraelectric phase of CH3NH3HgCl3. A structure for CH3NH3HgClBr2 is proposed. Raman spectra of polycrystalline samples of CH3NH3HgClBr2, CH3NH3HgCl3 and CH3NH3HgBr3 have been recorded. Assignments of most the observed bands are proposed. A comparative study of the spectra confirms the proposed structure.
R. Ben Hassen, A. Ben Salah