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MnSe is Vulcanite structured and crystallizes in the tetragonal P4/nmm space group. The structure is two-dimensional and consists of one MnSe sheet oriented in the (0, 0, 1) direction. Mn2+ is bonded to four equivalent Se2- atoms to form a mixture of distorted corner and edge-sharing MnSe4 tetrahedra. All Mn–Se bond lengths are 2.39 Å. Se2- is bonded in a 4-coordinate geometry to four equivalent Mn2+ atoms.
MnSe is Molybdenum Carbide MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mn2+ is bonded to six equivalent Se2- atoms to form a mixture of edge, face, and corner-sharing MnSe6 octahedra. The corner-sharing octahedral tilt angles are 49°. All Mn–Se bond lengths are 2.68 Å. Se2- is bonded in a 6-coordinate geometry to six equivalent Mn2+ atoms.
MnSe is Zincblende, Sphalerite structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Mn2+ is bonded to four equivalent Se2- atoms to form corner-sharing MnSe4 tetrahedra. All Mn–Se bond lengths are 2.58 Å. Se2- is bonded to four equivalent Mn2+ atoms to form corner-sharing SeMn4 tetrahedra.
MnSe is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Mn2+ is bonded to six equivalent Se2- atoms to form a mixture of corner and edge-sharing MnSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mn–Se bond lengths are 2.71 Å. Se2- is bonded to six equivalent Mn2+ atoms to form a mixture of corner and edge-sharing SeMn6 octahedra. The corner-sharing octahedral tilt angles are 0°.
MnSe is Wurtzite structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Mn2+ is bonded to four equivalent Se2- atoms to form corner-sharing MnSe4 tetrahedra. All Mn–Se bond lengths are 2.57 Å. Se2- is bonded to four equivalent Mn2+ atoms to form corner-sharing SeMn4 tetrahedra.
The structural, thermal, and electronic properties of Ba 2 MnSe 3 were investigated. Analysis of the low-temperature heat capacity revealed a low Debye temperature and a low average speed of sound that, together with the bonding in this material, result in a low thermal conductivity over a relatively large temperature range. Density functional theory and calculated electron localization were employed to investigate the electronic structure and bonding. Absorption and photoluminescence spectroscopy measurements corroborated our calculations and revealed a direct band gap of 1.75 eV. This study expands on our understanding of the physical properties of this material and reveals previously unascertained properties, the knowledge of which is imperative for any potential application of interest.
Phase analysis of systems Mn-S, Mn-Se and MnS-MnSe by X ray diffraction techniques, revealing homogeneity ranges
Phase equilibria in Mn-S, Mn-Se and MnS-MnSe systems by X ray diffraction after preparation by annealing
Iodine concentrations, temperature gradients and transport ampules etching effects on mass transport rate and crystal growth of MnS-MnSe- iodine system
Composition dependence of optical energy gap and diffuse reflectance in MnSe-CdSe solid solutions
MnSe-CdSe mixed crystals growth investigation by elements, binary compounds and solid solutions vapor transport properties
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The compound (Pb 2 MnSe 3 ) 0.6 VSe 2 was predicted to be kinetically stable based on density functional theory (DFT) calculations on an island of Pb 2 MnSe 3 between layers of VSe 2 . This approach provides a high degree of freedom by not forcing interlayer lattice match, making it ideal to investigate the likelihood of formation of new incommensurate layer misfit structures. The free space around the island is critical, as it allows atoms to diffuse and hence exploring the local energy landscape around the initial configuration. (Pb 2 MnSe 3 ) 0.6 VSe 2 was synthesized via a near diffusionless reaction from precursors where a repeating sequence of elemental layers matches the local composition and layer sequence of the predicted compound. The VSe 2 layer consists of a Se–V–Se trilayer with octahedral coordination of the V atoms. The Pb 2 MnSe 3 layer consists of three rock-salt-like planes, with a MnSe layer between the planes of PbSe. The center MnSe plane stabilizes the puckering of the outer PbSe layers. Electrical properties indicate that (Pb 2 Mn 1 Se 3 ) 0.6 VSe 2 undergoes a charge density wave transition at ~100 K and orders ferromagnetically at 35 K. Overall, the combination of theory and experiment enables a faster convergence to new heterostructures than either approach in isolation.
We report the magnetic properties and magnetic structure determination for a linear-chain antiferromagnet, MnBi 2 Se 4 . The crystal structure of this material contains chains of edge-sharing MnSe 6 octahedra separated by Bi atoms. The magnetic behavior is dominated by intrachain antiferromagnetic (AFM) interactions, as demonstrated by the negative Weiss constant of –74 K obtained by the Curie–Weiss fit of the paramagnetic susceptibility measured along the easy-axis magnetization direction. The relative shift of adjacent chains by one-half of the chain period causes spin frustration due to interchain AFM coupling, which leads to AFM ordering at TN = 15 K. Neutron diffraction studies reveal that the AFM ordered state exhibits an incommensurate helimagnetic structure with the propagation vector k = (0, 0.356, 0). The Mn moments are arranged perpendicular to the chain propagation direction (the crystallographic b axis), and the turn angle around the helix is 128°. The magnetic properties of MnBi2Se4 are discussed in comparison to other linear-chain antiferromagnets based on ternary mixed-metal halides and chalcogenides.
MnSe sublimation Knudsen measurements at various temperatures and pressures noting congruent vaporization