Crystal Structure and Hydrate Water Content of Synthetic Hellyerite, NiCO₃·5.5H₂O

Abstract

Abstract.A sample of pure, artificial hellyerite was synthesized in aqueous solution at 0°C. The recorded X-ray diffraction pattern completely agrees with the reference data given for natural hellyerite. Laboratory high resolution X-ray powder diffraction, applying global optimization methods and Rietveld refinement, was employed to solve the crystal structure. Synthetic hellyerite was determined to crystallize in the primitive monoclinic space group P2/m (no. 10) with a =

A routine for the determination of the microstructure of stacking-faulted nickel cobalt aluminium hydroxide precursors for lithium nickel cobalt aluminium oxide battery materials

“…The precursor samples L002 to L006 contain almost the same amount of intercalated water, between 2.3 and 2.8 wt%, which correlates with similar numbers of intercalation faults that were determined (Table 2). 11(b), cyan highlighted area], which can be assigned to the O-H bending mode of water molecules on the basis of the spectral data of NiCO 3 Á5.5H 2 O (Bette et al, 2016), Ni(OH) 2Àx (CO 3 ) x/2 ÁnH 2 O (Minkova et al, 1984) and Ni 12 (CO 3 ) 8 (OH) 8 Á(5-7)H 2 O (Rincke et al, 2015). The second decomposition step is associated both with the dehydration of hydroxide ions and with the decomposition of carbonate ions, as was observed during the thermal decomposition of nickel carbonate hydroxide salts (Rincke et al, 2015).…”

“…At $1650 cm À1 a broad and weak band is present in all spectra [ Fig. 11(b), cyan highlighted area], which can be assigned to the O-H bending mode of water molecules on the basis of the spectral data of NiCO 3 Á5.5H 2 O (Bette et al, 2016), Ni(OH) 2Àx (CO 3 ) x/2 ÁnH 2 O (Minkova et al, 1984) and Ni 12 (CO 3 ) 8 (OH) 8 Á(5-7)H 2 O (Rincke et al, 2015). Bands occurring in the spectral regions of 1050-1150, 1300-1400 and 1425-1500 cm À1 [Fig.…”

A new hydrate of magnesium carbonate, MgCO3·6H2O

“…CaCO 3 Á6H 2 O (ikaite; Hesse et al, 1983), and nickel, i.e. NiCO 3 Á5.5H 2 O (hellyerite; Bette et al, 2016). Our own investigations should elucidate the conditions of formation of the magnesium carbonate hydrates.…”

“…Other neutral carbonate hydrates of bivalent metal ions with a water content greater than five units per formula are only known for calcium (CaCO 3 Á6H 2 O) and nickel (NiCO 3 Á-5.5H 2 O). Like the title compound, these phases can be synthesized only at low temperatures of about 273.15 K and are transformed at room temperature to CaCO 3 (Coleyshaw et al, 2003) and amorphous nickel carbonate (Bette et al, 2016;Rincke, 2018), respectively.…”

Widgiemoolthalite

“…[11] As of 2016, the exact crystal structure of widgiemoolthalite was not known though based on the patterns produced when the mineral was analyzed with X-ray crystallography, a high degree of structural disorder was suspected (possible structure pictured in Figure 2). [12] [13] Under an optical microscope, Nickel, Robinson, and Mumme noted difficulty discerning individual crystals as their lateral dimensions were too small. [3] Crystals of widgiemoolthalite conform to a monoclinic system of symmetry, occupying space group P21/c.…”