Disorder in the composite crystal structure of the manganese `disilicide' MnSi_1.73from powder X-ray diffraction data

Abstract

The crystal structure of the higher manganese silicide MnSi1.7 (known in the literature as HMS) is investigated in samples with different compositions obtained by different techniques at temperatures not higher than 1273 K. Powder X-ray diffraction was applied. The crystal structure is described as incommensurate composite. In addition to the ordered model already known in the literature, the partial disorder in the silicon substructure was detected and described introducing an additional atomic site with a different modulation function.

Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide

“…S6), confirming a type of disorder intrinsic to this phase and restricting the amount of structural information available from single-crystal X-ray diffraction. Refinement of composite structures from powder diffraction data [38][39][40] , gives less detailed models than those obtained from single-crystal X-ray diffraction 39 as there is no reliable method to determine a modulation vector from powder data 38 . Therefore, as the starting point for refining the crystal structure from synchrotron powder X-ray data, we performed transmission electron microscopy and combined its results with the previously published model for (BiSe) 1.09 -TaSe 2 35,41 .…”

Stability and thermoelectric performance of doped higher manganese silicide materials solidified by RGS (ribbon growth on substrate) synthesis

“…If is an irrational number the structure is incommensurate and cannot be described using a single overall lattice parameter in the c direction: this motivates the structural characterization of HMS in terms of two separate subsystems or by the (3+1) dimensional superspace approach [9]. More recently another approach was proposed to model the XRD spectrum of the HMS structure by including significant defects in the Si sublattice [10]. The valence electron count ( ) concept is useful to describe the thermodynamic stability of chimney-ladder phases and to estimate the charge carrier density of these materials from the structural parameter γ [11][12][13][14].…”

Structural, Magnetic and Thermoelectric Properties of hp‐Mn3Ge5

“…Because of the mismatch between the two motifs, NCL compounds can adopt extremely long unit cells along the helix direction as well as incommensurately modulated or composite crystal structures , . The electronic transport properties of NCL compounds can be predicted on basis of the valence electron concentration per metal atom, VEC.…”

“…[1,32] Because of the mismatch between the two motifs, NCL compounds can adopt extremely long unit cells along the helix direction as well as incommensurately modulated or composite crystal structures. [1,[33][34][35][36][37] The electronic transport properties of NCL compounds can be predicted on basis of the valence electron concentration per metal atom, VEC. As in the related CrSi 2 , [38][39][40] a VEC of 14 sets the stage for a gap in the DOS about the Fermi level and semiconducting properties result.…”