Premium
Raman spectrum of layered jacutingaite (Pt 2 HgSe 3 ) crystals—Experimental and theoretical study
Author(s) -
Longuinhos Raphael,
Vymazalová Anna,
Cabral Alexandre R.,
Alexandre Simone S.,
Nunes Ricardo W.,
RibeiroSoares Jenaina
Publication year - 2020
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5764
Subject(s) - raman spectroscopy , density functional theory , phonon , van der waals force , condensed matter physics , spintronics , topological insulator , materials science , molecular physics , physics , quantum mechanics , molecule , ferromagnetism
Jacutingaite (Pt 2 HgSe 3 ) is a recently discovered layered platinum‐group mineral. Recent experimental studies have shown that it displays the properties of a quantum spin Hall insulator (QSHI), and theoretical studies indicate that its two‐dimensional monolayer is a QSHI with a robust topological gap of ∼0.5 eV. Jacutingaite is thus promising for potential applications to nanoelectronics and spintronics. The Raman spectrum of three‐dimensional bulk jacutingaite and the symmetries of its vibrational modes, fundamental for understanding structural modifications of this material, are still unexplored. Here, we address the zone‐center Raman optical phonons of bulk jacutingaite by experiments, symmetry, and first‐principles calculations. The improved synthesis used here provided crystals of higher purity and of micrometer size, allowing the study of single crystals. Polarized Raman spectroscopy was used to assign the symmetries of nine out of the 11 Raman‐active modes expected by group theory and their respective selection rules. The calculated wavenumbers of the Raman‐active modes, in addition to their atomic displacements, are in very good agreement with experiments. In addition, we discuss the use of different exchange correlation functionals within density functional theory, as local functionals and nonlocal functionals that best describe van der Waals interactions. The influence of the inclusion of spin–orbit coupling on calculated vibrational phonon wavenumbers and lattice parameters is commented, and it was found that the local density approximation provides a good description. Our results are of paramount importance to further exploitation of the effects of jacutingaite's structural modifications to tune its properties, as well as for its structural, optical, electronic, mechanical, and thermal applications.