Show simple item record

dc.contributor.authorArachchilage, Thilini
dc.date.accessioned2023-03-29T12:40:57Z
dc.date.available2023-03-29T12:40:57Z
dc.identifier.urihttp://hdl.handle.net/10464/17588
dc.description.abstractThe two-dimensional misfit layer dichalcogenide compounds [(MX)1+δ]m [(TX2)n] consist of alternating stackings of two subsystems of MX (Rock Salt) and TX2 (Transition metal dichalcogenide). Where, M = Sn, Pb, Bi, rare earth; X = S, Se; T = Ti, V, Nb, Ta, Cr. In Misfit layer compound (MLCs), at least one lattice parameter of the two subsystem unit cells should be incommensurate. m and n are integers that determine the stacking arrangement of MX and TX2 layers[1]. As a part of this research, attempts to synthesize single crystal of [(SnSe)1+δ]m [(V Se2)n] using a chemical vapour transport technique with I2 crystals as the transporting agent were carried out. Mixed crystals were formed with thin layers of [(SnSe)1+δ]m [(V Se2)n] present among the other byproduct materials. Monolayer, bilayer, and trilayer misfit layers were observed. The compositions and crystal structure of the misfit layer were investigated by Energy Dispersive X-ray spectroscopy and X-ray diffraction respectively. The parent compound, VSe2 was successfully synthesized as single crystal using the same method. Characteristic MLC vibrational modes were studied via optical Raman spectroscopy measurements and compared to the parent compound, VSe2. At 3.5 K, three characteristic vibrational modes are observed in the XX polarized Raman spectrum: Ag(1), Ag(2), Eg. Based on the observed Ag(1) mode in VSe2, the MLC Ag modes have been shifted. Those Raman frequencies for the intralayer vibrations of the VSe2 layers in the MLC deviate from that of the VSe2 crystals, which may be due to the charge 2 transfer from the SnSe layer to the VSe2 layer. In addition, the polar plots of the intensity of the MLC vibrational modes as a function of XX polarization angle are presented to study the symmetry of the vibrational mode. In comparison with the VSe2 Ag mode, both MLC Ag modes exhibit two-fold polarization anisotropy with a period of 180 degrees. This reveals that the site symmetry of the MLC is altered compared to VSe2.en_US
dc.subjectMisfit layer compounden_US
dc.subjectRaman vibrational mode symmetryen_US
dc.titlePREPARATION AND CHARACTERIZATION OF MISFIT CHALCOGENIDE [(SnSe)1+δ]m[VSe2]nen_US
refterms.dateFOA2023-03-23T00:00:00Z


Files in this item

Thumbnail
Name:
Brock_Thilini_Arachchilage.pdf
Size:
10.36Mb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record