| Records |
| Author |
Rakesh Roshan, S.C.; Yedukondalu, N.; Pandey, T.; Kunduru, L.; Muthaiah, R.; Rajaboina, R.K.; Ehm, L.; Parise, J.B. |
| Title |
Effect of atomic mass contrast on lattice thermal conductivity : a case study for alkali halides and alkaline-earth chalcogenides |
Type |
A1 Journal article |
Year  |
2023 |
Publication |
ACS applied electronic materials |
Abbreviated Journal |
|
| Volume |
5 |
Issue |
11 |
Pages |
5852-5863 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Lattice thermal conductivity (kappa(L)) is of great scientific interest for the development of efficient energy conversion technologies. Therefore, microscopic understanding of phonon transport is critically important for designing functional materials. In our previous study (Roshan et al., ACS Applied Energy Mater. 2021, 5, 882-896), anomalous kappa(L) trends were predicted for rocksalt alkaline-earth chalcogenides (AECs). In the present work, we extended it to alkali halides (AHs) and conducted a thorough investigation to explore the role of atomic mass contrast on lattice dynamics and phonon transport properties of 36 binary compounds (20 AHs + 16 AECs). The calculated spectral and cumulative kappa(L) reveal that low-lying optical phonon modes significantly boost kappa(L) alongside acoustic phonons in materials where the atomic mass ratio approaches unity and cophonocity nears zero. Phonon scattering rates are relatively low for materials with a mass ratio close to one, and the corresponding phonon lifetimes are higher, which enhances kappa(L). Phonon lifetimes play a critical role, outweighing phonon group velocities, in determining the anomalous trends in kappa(L) for both AHs and AECs. To further explore the role of atomic mass contrast in kappa(L), the effect of tensile lattice strain on phonon transport has also been investigated. Under tensile strain, both group velocities and phonon lifetimes decrease in the low frequency range, leading to a decrease in kappa(L). This work provides insights on how atomic mass contrast can tune the contribution of optical phonons to kappa(L) and its implications on scattering rates by either enhancing or suppressing kappa(L). These insights would aid in the selection of elements for designing new functional materials with and without atomic mass contrast to achieve relatively high and low kappa(L) values, respectively. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001096792500001 |
Publication Date |
2023-10-26 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2637-6113 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:201198 |
Serial |
9026 |
| Permanent link to this record |
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| Author |
Yedukondalu, N.; Pandey, T.; Roshan, S.C.R. |
| Title |
Effect of hydrostatic pressure on lone pair activity and phonon transport in Bi₂O₂S |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
|
| Volume |
6 |
Issue |
4 |
Pages |
2401-2411 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Dibismuth dioxychalcogenides, Bi2O2Ch (Ch = S, Se, Te), are a promising class of materials for next-generation electronics and thermoelectrics due to their ultrahigh carrier mobility and excellent air stability. An interesting member of this family is Bi2O2S, which has a stereochemically active 6s2 lone pair of Bi3+ cations, heterogeneous bonding, and a high mass contrast between its constituent elements. In the present study, we have used first-principles calculations in combination with Boltzmann transport theory to systematically investigate the effect of hydrostatic pressure on lattice dynamics and phonon transport properties of Bi2O2S. We found that the ambient Pnmn phase has a low average lattice thermal conductivity (kappa l) of 1.71 W/(m K) at 300 K. We also predicted that Bi2O2S undergoes a structural phase transition from a low-symmetry (Pnmn) to a high-symmetry (I4/mmm) structure at around 4 GPa due to centering of Bi3+ cations with pressure. Upon compression, the lone pair activity of Bi3+ cations is suppressed, which increases kappa l by almost 3 times to 4.92 W/ (m K) at 5 GPa for the I4/mmm phase. The computed phonon lifetimes and Gru''neisen parameters show that anharmonicity decreases with increasing pressure due to further suppression of the lone pair activity and strengthening of intra-and intermolecular interactions, leading to an average room-temperature kappa l of 12.82 W/(m K) at 20 GPa. Overall, this study provides a comprehensive understanding of the effect of hydrostatic pressure on the stereochemical activity of the lone pair of Bi3+ cations and its implications on the phonon transport properties of Bi2O2S. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000929103700001 |
Publication Date |
2023-02-08 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2574-0962 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.4 |
Times cited |
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Open Access |
Not_Open_Access |
| Notes |
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Approved |
Most recent IF: 6.4; 2023 IF: NA |
| Call Number |
UA @ admin @ c:irua:195245 |
Serial |
7300 |
| Permanent link to this record |
