Experimental and theoretical assessment of the Eu3+ doped Bi4Ge3O12

In this work, Bi ₄Ge ₃O ₁₂ doped with Eu ³⁺ was investigated experimentally and theoretically. The synthesis of several samples with different Eu ³⁺ concentrations was carried out by the polymeric precursor method. Photoluminescence spectroscopy was performed, and it shows the typical electronic transitions of Eu ³⁺. FTIR interpretation of samples allows us to infer that Eu ³⁺ substitutes not only Bi ³⁺ but also Ge ⁴⁺ . This interpretation was corroborated by ab initio calculations as both substitutions were found to be thermodynamically stable. Eu ³⁺ naturally takes on the Bi ³⁺ sites, producing ferromagnetic alignment; but when Eu ³⁺ takes on the Ge ⁴⁺ sites the alignment becomes antiferromagnetic. Since rare earth elements are particularly important in modifying the magnetic and luminescent properties of host materials, our findings open a new way to give a bi-functionality to the Bi ₄Ge ₃O ₁₂ material through selective doping.