scholarly journals Far-UV photoluminescence microscope for impurity domain in hexagonal-boron-nitride single crystals by high-pressure, high-temperature synthesis

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Kenji Watanabe ◽  
Takashi Taniguchi
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Boron Nitride ◽  
Single Crystals ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Layered Materials ◽  
High Pressure High Temperature ◽  
Far Ultraviolet

Abstract Hexagonal-boron-nitride single crystals grown by high-pressure, high-temperature (HPHT) synthesis are commonly used as the insulated substrate dielectric for two-dimensional (2D) atomic-layered materials like graphene and transition metal dichalcogenides (TMDs) to improve the flatness of the 2D materials atomically without disturbing the 2D electronic characteristics. However, HPHT single crystals often contain impure regions, which can hold subtle clues in regard to the 2D atomic-layered materials for new discoveries in the physics of 2D materials. To identify the position of the impure domains and to avoid them when the 2D devices are prepared, a far-ultraviolet photoluminescence microscope was developed. This microscope makes it possible to visualize the impure-growth region with ease in a no-contact and non-destructive manner.

scholarly journals Mechanochemical preparation of piezoelectric nanomaterials: BN, MoS2 and WS2 2D materials and their glycine-cocrystals

2020 ◽  
Vol 5 (2) ◽  
pp. 331-335 ◽  
Author(s):  
Viviana Jehová González ◽  
Antonio M. Rodríguez ◽  
Ismael Payo ◽  
Ester Vázquez
Keyword(s):  
Transition Metal ◽  
Boron Nitride ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Layered Materials ◽  
Molybdenum Disulphide ◽  
2D Layered Materials ◽  
Metal Dichalcogenides

Different 2D-layered materials of transition metal dichalcogenides (TMDCs) such as boron nitride (BN) or molybdenum disulphide (MoS2) have been theorised to have piezoelectric behaviour.

Notizen: Einkristall-Daten der Hochdruck-Hochtemperaturphase von CaSi2 / Structural Refinement of the High Pressure-High Temperature Phase of CaSi2

1982 ◽  
Vol 37 (11) ◽  
pp. 1487-1488 ◽  
Author(s):  
Jürgen Evers ◽  
Gilbert Oehlinger ◽  
Armin Weiss
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Structural Refinement ◽  
Interatomic Distances ◽  
High Pressure High Temperature

The high pressure-high temperature phase of CaSi2 is a representative of the α-ThSi2 type of structure. Single crystals grown at 40 kbar and 1000 °C enabled a structural refinement which leads to interatomic distances Si-Si: 229.9(1) pm (1 × ) and 240.0(1) pm (2 × ), Ca-Si: 309.4(4) pm (4 x ) and 323.9(4) pm (8 × ), Ca-Ca: 400.3(3) pm (4 × ) and 428.3(3) pm (4 × ).

scholarly journals Superhard Superconductor Composites Obtained by Sintering of Diamond, c-BN and C60 Powders with Superconductors

2006 ◽  
Vol 61 (12) ◽  
pp. 1541-1546 ◽  
Author(s):  
Gennadi A. Dubitsky ◽  
Vladimir D. Blank ◽  
Sergei G. Buga ◽  
Elena E. Semenova ◽  
Nadejda R. Serebryanaya ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Critical Temperature ◽  
Boron Nitride ◽  
Synthetic Diamond ◽  
Cubic Boron Nitride ◽  
High Pressure High Temperature ◽  
Diamond Powders

Superhard superconducting samples with a critical temperature of TC = 10.5 - 12.6 K were obtained by high-pressure / high-temperature sintering of synthetic diamond powders coated with a niobium film and in 50% - 50% composition with superhard C60 fullerene. Superhard superconductors with TC = 9.3 K were obtained when diamond and molybdenum powders were sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with TC = 36.1 - 37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.

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