Synthesis, Structural and Magnetic Characterization of a New Scheelite Related Compound: Eu₂Mo₃O₁₂

Abstract

Polycrystalline Eu2Mo3O12 has been synthesized and characterized by X‐ray and electron diffraction, high resolution electron microscopy and magnetic measurements. This oxide shows a complex scheelite superstructure whose essential feature is the existence of isolated Mo tetrahedra. Each Mo atom has four oxygen neighbors at distances ranging from 1.75 to 1.91 Å, whereas each Eu atom has eight oxygen neighbors at 2.43 Å. The temperature dependence of the inverse magnetic susceptibility shows that Eu2Mo3O12 behaves as a Curie–Weiss paramagnet at high temperature (160–300 K), whereas in the range 100–20 K it shows Van Vleck paramagnetism. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Validating the model of a (3 + 1)-dimensional incommensurately modulated structure as generator of a family of compounds for the Eu2(MoO4)3scheelite structure

“…The structure of Eu 2 (MoO 4 ) 3 , has already been determined on the basis of powder diffraction data collected by a conventional diffractometer [18]. The structure was solved in C2/c SG (monoclinic b axis) taking the Eu 2 (WoO 4 ) 3 crystallographic data [19] as a starting point.…”

“…The structure was solved in C2/c SG (monoclinic b axis) taking the Eu 2 (WoO 4 ) 3 crystallographic data [19] as a starting point. In this section, we will focus on the comparison between the results obtained from our refinement on the basis of synchrotron powder diffraction data and superspace model generated from KNd(MoO 4 ) 2 and those reported in [18].…”

“…Such sections correspond to the two inequivalent Mo atoms (t 0 ¼ 0, t 0 ¼ 1/3 or 2/3) and to the unique Eu atom, t 0 ¼ 1/3. Table 4 reports a comparison among the interatomic distances obtained from the supercell refinement and those reported in [18].…”

“…This space group corresponds to C2/c with the monoclinic axis b reported in [18] for Eu 2 (MoO 4 ) 3 . The refined lattice constants (Table 1, …”

“…Figure 2b shows the calculated and residual X-ray diffraction patterns. The atomic coordinates and main interatomic distances are listed in Tables 3 and 4 in comparison with those reported in [18].…”