@article{ISI:000478812300001,
 abstract = {Reversible switching of the structural ground state of a solid is a
fundamental goal in materials engineering, which has not been achieved
in atomically thin layers of van der Waals crystals. This is
particularly important for the transition metal dichalcogenides, such as
molybdenum disulphide (MoS2), where the higher-energy octahedral
polymorphs exhibit a wide range of fascinating properties. Here we show
that thermodynamically stable octahedral phase of monolayer MoS2 can be
achieved in coexistence with the 1H phase, at temperatures below similar
to 500 K, by forming a van der Waals hybrid with another layered solid,
such as hexagonal boron nitride (hBN) or graphene. Spatial mapping and
temperature-dependence of the zone-folded Raman modes reveal that the
octahedral phase exists only within the heterostructure region, and
exhibits remarkable stability to repeated thermal cycling. A concurrent
shift in the out-of-plane A1(g) vibrational mode of MoS2, and
near-absence of the octahedral phase in homo-epitaxial structures,
suggest likely role of local lattice relaxation due to
incommensurability-driven stress fields. Our experiment establishes van
der Waals hetero-epitaxy as a new tool for crystal structure engineering
in atomic membranes.},
 article-number = {041002},
 author = {Ahmed, Tanweer and Naik, Mit H. and Kumari, Simran and Suman, Smriti P.
and Debnath, Rahul and Dutta, Sudipta and Waghmare, V, Umesh and Jain,
Manish and Ghosh, Arindam},
 doi = {10.1088/2053-1583/ab2822},
 issn = {2053-1583},
 journal = {2D MATERIALS},
 month = {OCT},
 number = {4},
 orcid-numbers = {Jain, Manish/0000-0001-9329-6434
Suman, Smriti Prakash/0000-0001-9511-4710
Ahmed, Tanweer/0000-0002-5921-8405},
 researcherid-numbers = {Jain, Manish/A-8303-2010
},
 times-cited = {5},
 title = {Thermodynamically stable octahedral MoS2 in van der Waals
hetero-bilayers},
 unique-id = {ISI:000478812300001},
 volume = {6},
 year = {2019}
}