Temperature Dependent Structural Evolution of WSe2: A Synchrotron X-ray Diffraction Study

被引：24

作者：

Mathew, Sinu ^{[1
,2
]}

Abraham, Aben Regi ^{[2
]}

Chintalapati, Sandhya ^{[3
]}

Sarkar, Soumya ^{[1
]}

Joseph, Boby ^{[4
]}

Venkatesan, Thirumalai ^{[1
,5
]}

机构：

[1] Natl Univ Singapore, NUSNNI NanoCore, Singapore 117411, Singapore

[2] Mahatma Gandhi Univ, SB Coll, Dept Phys, Kottayam 686101, Kerala, India

[3] Tata Inst Fundamental Res, Ctr Interdisciplinary Sci, Hyderabad 500107, India

[4] Elettra Sincrotrone, Str Statale 14 Km 1635 Area Sci Pk, I-34149 Trieste, Italy

[5] Natl Univ Singapore, Dept Mat Sci & Engn, Singapore 117575, Singapore

来源：

CONDENSED MATTER | 2020年 / 5卷 / 04期

关键词：

two-dimensional systems; transition metal dichalcogenides; WSe2; X-ray powder diffraction; Debye temperature; TRANSITION-METAL DICHALCOGENIDES; THERMAL-EXPANSION; 2H-MOS2; SPECTRA; 2H-WSE2; MOSE2;

D O I：

10.3390/condmat5040076

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

A thorough investigation of the structural parameters of micromechanically exfoliated multilayer WSe2 flakes was undertaken between 400 K to 110 K. Crystal structure of WSe2 remains in the trigonal prismatic structure in this temperature range, however, with a clear difference in the temperature dependence of the in-plane a, and the out-of-plane c, lattice parameters. The linear coefficients of thermal expansion of a and c are 5.132 x 10(-6)/K and 8.105 x 10(-6)/K, respectively. The temperature dependence of the unit-cell volume is analyzed using zero-pressure equation-of-state which yielded the Debye temperature of the WSe2 to be 160 K. Following the temperature dependence of the W-Se and W-W bond distances, a nonlinear behavior is observed in the former in contrast to a rather regular behavior of the later. This significant difference in the temperature dependence of the a and c lattice parameters can have consequences in the macroscopic physical properties of the system. A good correlation between the temperature dependence of the W-Se bond distance and Raman E2g1 mode has been observed.

引用

页码：1 / 9

页数：9

共 27 条

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