%0 Journal Article
%A Yang, Xiaohui
%A Bao, Jin-Ke
%A Lou, Zhefeng
%A Li, Peng
%A Jiang, Chenxi
%A Wang, Jialu
%A Sun, Tulai
%A Liu, Yabin
%A Guo, Wei
%A Ramakrishnan, Sitaram
%A Kotla, Surya Rohith
%A Tolkiehn, Martin
%A Paulmann, Carsten
%A Cao, Guang-Han
%A Nie, Yuefeng
%A Li, Wenbin
%A Liu, Yang
%A van Smaalen, Sander
%A Lin, Xiao
%A Xu, Zhu-An
%T Commensurate Stacking Phase Transitions in an Intercalated Transition Metal Dichalcogenide
%J Advanced materials
%V 34
%N 6
%@ 0935-9648
%C Weinheim
%I Wiley-VCH
%M PUBDB-2022-00563
%P 2108550 -
%D 2022
%Z Waiting for fulltext
%X Intercalation and stacking-order modulation are two active ways in manipulating the interlayer interaction of transition metal dichalcogenides (TMDCs), which lead to a variety of emergent phases and allow for engineering material properties. Herein, the growth of Pb-intercalated TMDCs–Pb(Ta<sub>1+x</sub>Se<sub>2</sub>)<sub>2</sub>, the first 124-phase, is reported. Pb(Ta<sub>1+x</sub>Se<sub>2</sub>)<sub>2</sub> exhibits a unique two-step first-order structural phase transition at around 230 K. The transitions are solely associated with the stacking degree of freedom, evolving from a high-temperature (high-T) phase with ABC stacking and R3m symmetry to an intermediate phase with AB stacking and P3m1, and finally to a low-temperature (low-T) phase again with R<sub>3</sub>msymmetry, but with ACB stacking. Each step involves a rigid slide of building blocks by a vector [1/3, 2/3, 0]. Intriguingly, gigantic lattice contractions occur at the transitions on warming. At low-T, bulk superconductivity with Tc ≈ 1.8 K is observed. The underlying physics of the structural phase transitions are discussed from first-principle calculations. The symmetry analysis reveals topological nodal lines in the band structure. The results demonstrate the possibility of realizing higher-order metal-intercalated phases of TMDCs and advance the knowledge of polymorphic transitions, and may inspire stacking-order engineering in TMDCs and beyond.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:34871466
%U <Go to ISI:>//WOS:000732521900001
%R 10.1002/adma.202108550
%U https://bib-pubdb1.desy.de/record/474173