Abstract
Powder X-ray diffraction, variable temperature magnetic susceptibility, and zero-field Mössbauer spectroscopy measurements were used to characterize the new phase Li 2Fe 2(MoO 4) 3. This material is obtained simply by the mixing of solutions of lithium iodide in acetonitrile with solid Fe 2(MoO 4) 3 at ambient temperature. The reaction is entirely reversible using bromine as an oxidant. Li 2Fe 2(MoO 4) 3 possesses the high-temperature orthorhombic ferric molybdate structure and Guinier photographs were completely indexed in space group Pnca with cell constants a = 9.3483(5), b = 12.8974(9), and c = 9.4941(6) Å versus the monoclinic ( P2 1 a ) Fe 2(MoO 4) 3 precursor phase. Chemical analytical data, room-temperature magnetic susceptibility and Mössbauer spectroscopy indicate essentially complete stoichiometric reduction of the latter compound. Magnetic hyperfine splitting of the zero field Mössbauer spectrum below 12.5 K indicates a three-dimensional magnetically ordered state which susceptibility results show to be weakly ferromagnetic owing to probable canting of antiferromagnetically coupled lattices. Above ∼40 K, the material obeys a Curie-Weiss law whose parameters are C = 3.51 emu/mole, μ eff = 5.30 β and ϑ = −19 K.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
