Crystallization and phase transitions of C6H6: C6F6 complex under extreme conditions using laser-driven shock

Ashutosh Mohan; S. Chaurasia; John Richard Pasley

doi:10.1063/5.0084920

Crystallization and phase transitions of C6H6: C6F6 complex under extreme conditions using laser-driven shock

Ashutosh Mohan, S. Chaurasia, John Richard Pasley

Physics

Research output: Contribution to journal › Article › peer-review

Abstract

The C6H6:C6F6 cocrystal is one of the simplest organic cocrystals with a molecule having a C–F bond and without any hydrogen bonding. It has a crystal structure very different from its constituents, C6H6 and C6F6, and its higher melting point indicates its increased stability relative to these two materials. So far, no studies are available on the phase transitions of this interesting adduct under dynamic compression. In this study, we present the findings of phase transitions of an equimolar mixture of C6H6:C6F6 observed under rapid shock compression at pressures of up to 4.15 GPa using time-resolved Raman spectroscopy. The compression is driven by a 2 J Nd:YAG laser with an 8 ns pulse length. Four prominent modes at 370 cm−1 (ν10F mode), 443 cm−1 (ν6F mode), 560 cm−1 (ν1F mode), and 991 cm−1 (ν1H mode) exhibit a blue shift with scaling factors of 2.41, 2.26, 2.39, and 2.67 cm−1/GPa, respectively. The liquid → solid-I phase transition is observed at around 0.49 GPa shock pressure. The second phase transition from solid-I → solid-VI is observed between 1.32 and 2.60 GPa, and no signature of the solid-V phase is observed unlike in the case of static compression[Wang et al., J. Phys. Chem. C 120, 29510 (2016)]. Another phase transition solid-VI → solid-VII is observed between 3.9 and 4.15 GPa. The shock velocities in the sample at two laser intensities, 1.47 GW/cm2 (300 mJ) and 2.46 GW/cm2 (500 mJ), are calculated by measuring the intensity ratio of Raman modes emerging from the shocked region to that of the whole sample and are 3.13 and 4.05 km/s, respectively. To compare with the experimental results, 1D radiation hydrodynamics simulations are also performed. The experimental and simulated shock velocities are in good agreement. The mode Grüneisen parameter for the ν1H, ν1F, ν6F, ν10F, and ν10' F modes are γi = 0.011(2), 0.022(2), 0.011(1), 0.024(3), and 0.379(14), respectively.

Original language	English
Article number	115903
Number of pages	10
Journal	Journal of Applied Physics
Volume	131
DOIs	https://doi.org/10.1063/5.0084920
Publication status	Published - 17 Mar 2022

Bibliographical note

© 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

Access to Document

10.1063/5.0084920

Revised Manuscript
© 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details
Accepted author manuscript, 1.95 MB

Cite this

@article{f1635198682041d88e7f229cbfd14246,

title = "Crystallization and phase transitions of C6H6: C6F6 complex under extreme conditions using laser-driven shock",

abstract = "The C6H6:C6F6 cocrystal is one of the simplest organic cocrystals with a molecule having a C–F bond and without any hydrogen bonding. It has a crystal structure very different from its constituents, C6H6 and C6F6, and its higher melting point indicates its increased stability relative to these two materials. So far, no studies are available on the phase transitions of this interesting adduct under dynamic compression. In this study, we present the findings of phase transitions of an equimolar mixture of C6H6:C6F6 observed under rapid shock compression at pressures of up to 4.15 GPa using time-resolved Raman spectroscopy. The compression is driven by a 2 J Nd:YAG laser with an 8 ns pulse length. Four prominent modes at 370 cm−1 (ν10F mode), 443 cm−1 (ν6F mode), 560 cm−1 (ν1F mode), and 991 cm−1 (ν1H mode) exhibit a blue shift with scaling factors of 2.41, 2.26, 2.39, and 2.67 cm−1/GPa, respectively. The liquid → solid-I phase transition is observed at around 0.49 GPa shock pressure. The second phase transition from solid-I → solid-VI is observed between 1.32 and 2.60 GPa, and no signature of the solid-V phase is observed unlike in the case of static compression[Wang et al., J. Phys. Chem. C 120, 29510 (2016)]. Another phase transition solid-VI → solid-VII is observed between 3.9 and 4.15 GPa. The shock velocities in the sample at two laser intensities, 1.47 GW/cm2 (300 mJ) and 2.46 GW/cm2 (500 mJ), are calculated by measuring the intensity ratio of Raman modes emerging from the shocked region to that of the whole sample and are 3.13 and 4.05 km/s, respectively. To compare with the experimental results, 1D radiation hydrodynamics simulations are also performed. The experimental and simulated shock velocities are in good agreement. The mode Gr{\"u}neisen parameter for the ν1H, ν1F, ν6F, ν10F, and ν10' F modes are γi = 0.011(2), 0.022(2), 0.011(1), 0.024(3), and 0.379(14), respectively.",

author = "Ashutosh Mohan and S. Chaurasia and Pasley, {John Richard}",

note = "{\textcopyright} 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher{\textquoteright}s self-archiving policy. Further copying may not be permitted; contact the publisher for details ",

year = "2022",

month = mar,

day = "17",

doi = "10.1063/5.0084920",

language = "English",

volume = "131",

journal = "Journal of Applied Physics",

issn = "0021-8979",

publisher = "American Institute of Physics",

}

TY - JOUR

T1 - Crystallization and phase transitions of C6H6

T2 - C6F6 complex under extreme conditions using laser-driven shock

AU - Mohan, Ashutosh

AU - Chaurasia, S.

AU - Pasley, John Richard

N1 - © 2022 Author(s). This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2022/3/17

Y1 - 2022/3/17

N2 - The C6H6:C6F6 cocrystal is one of the simplest organic cocrystals with a molecule having a C–F bond and without any hydrogen bonding. It has a crystal structure very different from its constituents, C6H6 and C6F6, and its higher melting point indicates its increased stability relative to these two materials. So far, no studies are available on the phase transitions of this interesting adduct under dynamic compression. In this study, we present the findings of phase transitions of an equimolar mixture of C6H6:C6F6 observed under rapid shock compression at pressures of up to 4.15 GPa using time-resolved Raman spectroscopy. The compression is driven by a 2 J Nd:YAG laser with an 8 ns pulse length. Four prominent modes at 370 cm−1 (ν10F mode), 443 cm−1 (ν6F mode), 560 cm−1 (ν1F mode), and 991 cm−1 (ν1H mode) exhibit a blue shift with scaling factors of 2.41, 2.26, 2.39, and 2.67 cm−1/GPa, respectively. The liquid → solid-I phase transition is observed at around 0.49 GPa shock pressure. The second phase transition from solid-I → solid-VI is observed between 1.32 and 2.60 GPa, and no signature of the solid-V phase is observed unlike in the case of static compression[Wang et al., J. Phys. Chem. C 120, 29510 (2016)]. Another phase transition solid-VI → solid-VII is observed between 3.9 and 4.15 GPa. The shock velocities in the sample at two laser intensities, 1.47 GW/cm2 (300 mJ) and 2.46 GW/cm2 (500 mJ), are calculated by measuring the intensity ratio of Raman modes emerging from the shocked region to that of the whole sample and are 3.13 and 4.05 km/s, respectively. To compare with the experimental results, 1D radiation hydrodynamics simulations are also performed. The experimental and simulated shock velocities are in good agreement. The mode Grüneisen parameter for the ν1H, ν1F, ν6F, ν10F, and ν10' F modes are γi = 0.011(2), 0.022(2), 0.011(1), 0.024(3), and 0.379(14), respectively.

AB - The C6H6:C6F6 cocrystal is one of the simplest organic cocrystals with a molecule having a C–F bond and without any hydrogen bonding. It has a crystal structure very different from its constituents, C6H6 and C6F6, and its higher melting point indicates its increased stability relative to these two materials. So far, no studies are available on the phase transitions of this interesting adduct under dynamic compression. In this study, we present the findings of phase transitions of an equimolar mixture of C6H6:C6F6 observed under rapid shock compression at pressures of up to 4.15 GPa using time-resolved Raman spectroscopy. The compression is driven by a 2 J Nd:YAG laser with an 8 ns pulse length. Four prominent modes at 370 cm−1 (ν10F mode), 443 cm−1 (ν6F mode), 560 cm−1 (ν1F mode), and 991 cm−1 (ν1H mode) exhibit a blue shift with scaling factors of 2.41, 2.26, 2.39, and 2.67 cm−1/GPa, respectively. The liquid → solid-I phase transition is observed at around 0.49 GPa shock pressure. The second phase transition from solid-I → solid-VI is observed between 1.32 and 2.60 GPa, and no signature of the solid-V phase is observed unlike in the case of static compression[Wang et al., J. Phys. Chem. C 120, 29510 (2016)]. Another phase transition solid-VI → solid-VII is observed between 3.9 and 4.15 GPa. The shock velocities in the sample at two laser intensities, 1.47 GW/cm2 (300 mJ) and 2.46 GW/cm2 (500 mJ), are calculated by measuring the intensity ratio of Raman modes emerging from the shocked region to that of the whole sample and are 3.13 and 4.05 km/s, respectively. To compare with the experimental results, 1D radiation hydrodynamics simulations are also performed. The experimental and simulated shock velocities are in good agreement. The mode Grüneisen parameter for the ν1H, ν1F, ν6F, ν10F, and ν10' F modes are γi = 0.011(2), 0.022(2), 0.011(1), 0.024(3), and 0.379(14), respectively.

U2 - 10.1063/5.0084920

DO - 10.1063/5.0084920

M3 - Article

SN - 0021-8979

VL - 131

JO - Journal of Applied Physics

JF - Journal of Applied Physics

M1 - 115903

ER -