The crystal structure of a lithium–nickel molybdate, Li₂Ni₂Mo₃O₁₂, and the systematics of the structure type

Abstract

Li2Ni2Mo3Ol2 is orthorhombic, a = 10.423 (3), b --17.525 (4), c = 5-074 (1) A, space group Pmcn with Z = 4. 2717 independent reflexions were collected and the structure was refined to an R value of 0.053. The average Mo-O and (Ni,Li)-O distances are 1.774 and 2.097 A, respectively. The close-packed sheets of O are composed of three-square-wide bands of Wells's No. 9 regular net, held together by semi-regular single chains of triangles. There are two identical sheets in the stacking sequence, and the regular and semi-regular voids between the O atoms are filled by the cations: Ni and Li occupy, in various proportions, the trigonal prism (M1), the distorted (M2) and the regular (M3) trigonal antiprisms, and Mo occupies the elongated tetrahedral voids. ExperimentalSingle crystals of Li2Ni2Mo3Oi2 were produced accidentally during an attempt to grow nickel-olivine crystals by a flux method (Ozima & Zoltai, 1976). One of these crystals, 0.07 × 0.07 x 0-08 mm, was mounted on an automated, four-circle Rigaku diffractometer and three-dimensional intensities were collected with Mo Ka radiation, monochromated by a graphite plate.The intensities of the reflexions were collected in the o9-20 mode. The intensities of three standard reflexions were checked after every 50 measurements. 2980 independent intensities were collected up to 20 = 80 °. Of these, 2717 intensities were sufficiently strong for consideration. All intensities were corrected for Lorentz and polarization effects, but no corrections were made for primary and secondary extinction, or for absorption. The last appeared to be unnecessary as the crystal was almost an equidimensional cube. Structure determination and refinementThree-dimensional Patterson maps were computed and were solved for the Mo and Ni atomic coordinates by recognition of the vectors of these relatively heavy atoms. The locations of the O and Li atoms were obtained from a Fourier difference synthesis. The structure was subsequently refined by minimizing E (IFol --IFcl) 2 through full-matrix least-squares calculations based on the 2717 observed intensities. Anisotropic thermal parameters for Mo, Ni and O and isotropic thermal parameters for Li were also calculated. The final R value obtained was 0.053. The atomic coordinates are given in Table 1. The Ni-Li distribution pattern in M1, M2 and M3 sites was also determined. The M1 site is occupied by Li and the M2 and M3 sites by Ni and Li in the ratio Ni : Li 0-731:0.269 and 0.538:0.462 respectively.

A Visible‐Light‐Driven Photocatalyst of NASICON Li2Ni2(MoO4)3 Nanoparticles

“…This is in agreement with Ozima et al. 's report: a = 10.423(3) Å, b = 17.525(4) Å, c = 5.074(1) Å, α = β = γ = 90° and V = 926.83(39) Å 3 .…”

“…reported that Li 2 Ni 2 (MoO 4 ) 3 phase has a high‐voltage redox behavior with a discharge capacity of ≈115 mAh/g . Li 2 Ni 2 (MoO 4 ) 3 is intriguing in the rechargeable lithium ion technology as a potential cathode materials for lithium batteries …”

Unique Colours of 3d‐Transition‐Metal‐Substituted Lyonsite Molybdates and Their Derivatives: The Role of Multiple Coordination Geometries and Metal‐to‐Metal Charge Transfer

“…700 °C) brilliantly coloured Li 3 Al 1– x M III x (MoO 4 ) 3 (0 < x ≤ 1.0) for M III = Cr (brown) and Fe (yellow‐green) and Li 3– x Al 1– x M II 2 x (MoO 4 ) 3 (0< x ≤ 1.0) for M II = Co (purple‐blue), Ni (yellow) and Cu (parrot green). Powder X‐ray diffraction (PXRD) together with scanning electron microscopy (SEM) images (Figure and Figures S2 and S3 in the Supporting Information) show that Li 3 Al 1– x M III x (MoO 4 ) 3 (M III = Cr, Fe) and Li 3– x Al 1– x M II 2 x (MoO 4 ) 3 (M II = Co, Ni, Cu) are essentially single‐phase solids isostructural with the parent lyonsite‐type oxides Li 3 Al(MoO 4 ) 3 , Li 3 Cr(MoO 4 ) 3 , Li 3 Fe(MoO 4 ) 3 , Li 2 Mg 2 (MoO 4 ) 3 ,, Li 2 Co 2 (MoO 4 ) 3 , Li 2 Ni 2 (MoO 4 ) 3 and Li 2 Cu 2 (MoO 4 ) 3 …”

X-ray diffraction and vibrational Raman spectra of the Li2−Na Co2(MoO4)3 (0 ⩽x⩽ 1.4) solid solution with a lyonsite structure

“…M 2+ + h), in these materials, one can expect that these binary molybdate compounds could be nonstoichiometric. Moreover, according to Ozima et al [26], the respective occupancies of the sites in the lyonsite structure may all be dependent on temperature of formation or kinetic influences, availability of cations, and also possible oxidation of cations. A closer look to the occupation of the M(1), M(2) and M(3) sites indicates that all three positions are partially occupied by Co, Na and Li with different site occupations, and particularly in Li 2 Co 2 (MoO 4 ) 3 with the highest Li:Co ratio being 0.79:0.21 on the trigonal-prismatic site, and the lowest Li:Co ratio being 0.34:0.66 on the edge sharing octahedral site in agreement with the literature data [27].…”

“…Atomic positions of the orthorhombic Li 2 Co 2 (MoO 4 ) 3 [24], (Pnma), were used as the initial input for the Table 1 Cell parameters and merite factors of the Li 2-x Na x Co 2 (MoO 4 ) 3 compositions. The observed, calculated and the difference of the X-ray diffraction patterns for samples with compositions x = 0.6 and 1.4 are given in Fig.…”