Single Crystal Structural Investigations on NiyMo6Se8−xSx Solid Solution: A New Location of Nickel Counterions

In Situ Synchrotron Powder Diffraction Study of Cd Intercalation into Chevrel Phases: Crystal Structure and Kinetic Effect

“…Such procedure has been performed by the use of sequential Rietveld refinements, as coded in the FullProf code 30 but limiting the refinement to the three ranges in which the selected reflection (using hexagonal setting ( due to a larger atomic radius of Se with respect to S, 1.20 Å versus 1.05 Å, respectively 34 . The refined atomic parameters and selected interatomic distances for both phases are summarized in supplementary materials and are in good agreement with previous reports 1,7,22,28,35 .…”

“…32 The refined atomic parameters and selected interatomic distances for both phases are summarized in the Supporting Information and are in good agreement with previous reports. 1,19,26,33,34 However, as a result of the high counting statistics and resolution of synchrotron powder diffraction, a few spurious peaks were detected and are ascribed to minor impurity phases (less than 1%) such as MoSe 2 and MoS 2 and probably a few cluster condensed phases not detected during preliminary powder characterization. Analysis of peak broadening using profile coefficients from the Rietveld refinement showed a small isotropic broadening due to internal strain (average maximum strains of 7.43(3) × 10 −4 and 6.02(3) 10 −4 for Mo 6 Se 8 and Mo 6 S 8 , respectively), while broadening due to crystallite size was detected only for Mo 6 S 8 , with an average size of 3.06(1) μm.…”

Phase Diagram of Mg Insertion into Chevrel Phases, MgxMo6T8 (T = S, Se). 1. Crystal Structure of the Sulfides

“…It is a stacking of Mo 6 T 8 blocks composed of the octahedral cluster of molybdenum atoms inside the anion cube. In contrast, a variety of different cation locations were discovered in the CPs. ,,− From three types of cavities, formed between Mo 6 T 8 blocks (Figure ), only two of them (cavities 1 and 2) can be filled by cations of ternary metals, because a strong repulsion of the Mo atoms does not allow the occupation of cavity 3. In earlier works, devoted to the CPs, a simple scheme of the cation distribution was proposed. , According to this scheme, the cation position in the crystal structure depends mainly on its size.…”

The transition element sulfo-selenide Chevrel phases: A new way to stabilize the Mo6(S,Se)8 framework

“…The ternary M y Mo 6 Se 8 molybdenum selenides with M a transition element (Cr, Ti, Fe, Co, and Ni) and sulfo-selenides (S,Se) 8 with nickel ion have recently been investigated [1][2][3].They present new occupancies of the transition metal ions in the cavities of the tridimensional channels of the crystalline structure and form a new original family of Chevrel phases, as derivatives of the well-known Chevrel phases.…”

“…Let us remark that the location of the metal ions in the cavities 2 is different between the classical Chevrel phases (site M(2)) and these selenides (site M(2 )). Furthermore, both these different positions in the cavity 2 can be partly occupied in the same Ni y Mo 6 (S,Se) 8 compound [3]. These selenide Chevrel phases are promising materials for thermoelectric applications [4].…”