Composition and crystal structures of double molybdates of uni- and bivalent metals

Abstract

we established the following: l) Tautomerism. In the crystals of all compounds, the molecules exist in the asymmetric tautomeric form. The ring proton is located near the donor (II) and far from the acceptor (IV) substituent. 2) Conformation. The substituents are insignificantly inclined to the ring plane. Only (III) is not flat. The bis-nitrotriazolyl molecules are centrosymmetric (V) or pseudocentrosymmetric (VI). 3) Molecular interaction. The ring proton participates in strong hydrogen bonds in the crystals of all compounds. All triazole molecules, except (V), interact by N-H ... N hydrogen bonding. The triazole ring in (V) is connected with water molecules by N-H ... O bonds. Vander Waals forces represent the main bond type in this crystal.

The effect of pressure on luminescence properties of Cr3+ ions in LiSc(WO4)2 crystals—Part I: Pressure dependent emission lineshape

“…Cr 3+ -doped LiSc(WO 4 ) 2 single crystal doped with 0.5 wt% of Cr 3+ were grown by a melting method developed by Klevtsov et al [4]. The details were described in our previous paper [23].…”

“…Trivalent chromium (Cr 3+ )-doped materials are promising candidates for designing new efficient laser materials over this tuning range principally because low field Cr 3+ systems have an efficient spin-allowed, vibronic 4 T 2 -4 A 2 emission whose energy is proportional to crystal field strength (Dq) and varies widely over host lattices [2]. A family of double tungstates and molybdates [M I M III (M VI O 4 ) 2 , where M I ¼ alkali earth metals; M III ¼ transition metals or rare earths and M VI ¼ Mo or W] are found to exist in polymorphic forms [3][4][5][6][7] and to have promising optical, antiferroelectric and ferroelastic properties [8][9][10][11][12][13][14][15][16]. They have been already shown to be excellent host materials for optical activators like transition metal and rare earth ions [8][9][10][11][12][13][14].…”

Neutron scattering study of the layered Ising magnet CsDy(MoO4)2

“…Å [3]. This structure is essentially the same as for CsPr(MoO 4 ) 2 [16]. The most prominent feature is a stacking of alternating layers along the crystallographic a-axis: -Dy-(MoO 4 )-Cs-(MoO 4 )- (Fig.…”

“…Although neutron diffraction has been widely used in the study of crystal structures [1,3,14], we were surprised not to find any reports in the literature on magnetic neutron scattering experiments on DRMs. Although magnetic neutron diffraction often is the «ultimate» technique for studying magnetic phase transitions and critical behavior, actual experiments may be, from a purely technical point of view, nontrivial to carry out.…”

“…Double rare-earth molybdates (DRMs) with the general formula MR(MoO 4 ) 2 (R = rare earth, M = alkali metal) crystallize in a variety of layered structures (see for example Refs. [1][2][3][4] and are a large family of 2D compounds with some very interesting species. The magnetism of molybdates is entirely due to the presence of trivalent rare-earth ions.…”