Magnetic circular dichroism in Na3Eu(C4H4O5)3·2NaClO4·6H2O

Abstract

The absorption and magnetic circular dichroism (m.c.d.) of Na₃Eu(C₄H₄O₅)₃·2NaClO₄·6H₂O single crystals have been measured at 100 K for the transitions ⁷F₀→⁵D_1,2˙ Transitions were observed to three levels that are doubly degenerate in the D₃ site symmetry appropriate for the room-temperature crystal structure. Magnetic moments were determined as A/D for the levels ⁵D₁(E)=–1.4, ⁵D₂(1E)= 1.2 and ⁵D₂(2E)=–0.09. The occurence of a crystallographic phase transition was verified. The data could not be explained using either D₃, the room-temperature site symmetry, or C₂, the low-temperature site symmetry, alone. Rather a combination of these two symmetries was needed.