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Prediction of Mechanical Properties and Thermodynamic Stability of Ti-N system using MTP Interatomic Potential
Authors:
Pradeep Kumar Rana,
Atharva Vyawahare,
Rohit Batra,
Satyesh Kumar Yadav
Abstract:
Ti-N material system have range of compounds with different stoichiometry like Ti2N, Ti3N2, Ti6N5, Ti4N3 alongwith Ti , TiN and solid solutions of N in Ti with a maximum of 23% solubility. In this work, we develop an interatomic potential based on moment tensor potential (MTP) that could reliably predict mechanical properties and thermodynamic stability of all Ti-N system. Taking into account the…
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Ti-N material system have range of compounds with different stoichiometry like Ti2N, Ti3N2, Ti6N5, Ti4N3 alongwith Ti , TiN and solid solutions of N in Ti with a maximum of 23% solubility. In this work, we develop an interatomic potential based on moment tensor potential (MTP) that could reliably predict mechanical properties and thermodynamic stability of all Ti-N system. Taking into account the structural similarity and dissimilarity of various Ti-N system to choose training dataset was crucial for development of the potential. Root mean square error (RMSE) in prediction of formation energy using MTP potential compared to one calculated using density functional theory (DFT) for training dataset is 2.1 meV/atom and for testing dataset is 6.8 meV/atom. The frequency of absolute error in formation energy peaks at a maximum value of 3.8 meV/atom for system that was part of training dataset, while it peaks at 7.6 meV/atom for systems that are not part of the training dataset. Furthermore, the distribution and variability of elastic constants across compositions are systematically evaluated, revealing trends consistent with DFT benchmarks. The developed potential was used to predict energy of new phases in Ti-N system. We show that structures with N/Ti ratios ranging from 0 to 1 can be thermodynamically stable. A maximum deviation of 10 meV/atom from the convex hull plot of formation energy 0K was observed for a few system.
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Submitted 24 July, 2025;
originally announced July 2025.
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Stabilizing ultrathin Silver (Ag) films on different substrates
Authors:
Allamula Ashok,
Pradeep Kumar Rana,
Daljin Jacob,
Peela Lasya,
P Muhammed Razi,
Satyesh Kumar Yadav
Abstract:
This paper reports an effective method of stabilizing ultrathin Silver (Ag) films on substrates using a filler metal (Zn). Ag films with a thickness < 15 nm were deposited by DC magnetron sputtering above a Zn filler metal on glass, quartz, silicon and PET (polyethylene terephthalate) substrates. Zinc is expected to partially or fully fill the roughness associated with the substrates. The Zn fille…
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This paper reports an effective method of stabilizing ultrathin Silver (Ag) films on substrates using a filler metal (Zn). Ag films with a thickness < 15 nm were deposited by DC magnetron sputtering above a Zn filler metal on glass, quartz, silicon and PET (polyethylene terephthalate) substrates. Zinc is expected to partially or fully fill the roughness associated with the substrates. The Zn filler material and ultrathin Ag film form a 3-D augmented atomically chemically graded interface. 3-D interfaces have smoothly varying chemistry. The ability of Zn to partially or fully fill the substrate roughness improves the adhesion of Zn along with the Ag to the substrate. Also, Zn acts as a barrier layer against the diffusion of Ag into the substrate. This technique leads to ultrathin Ag films with low sheet resistance (~ 3 Ω/Sq.), low mean absolute surface roughness (~1 nm), good optical transparency (~ 65 %), better stability and compatibility with the environment. The results indicate significant potential for applying stable ultrathin Ag film/electrode as a practical and economically feasible design solution for optoelectronic (transparent and conductive electrodes for solar cells and LEDs) and plasmonic devices. This film shows good conductivity, transparency, stability, and flexibility.
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Submitted 27 June, 2023;
originally announced June 2023.
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Original Research By Young Twinkle Students (ORBYTS): Ephemeris Refinement of Transiting Exoplanets
Authors:
Billy Edwards,
Quentin Changeat,
Kai Hou Yip,
Angelos Tsiaras,
Jake Taylor,
Bilal Akhtar,
Josef AlDaghir,
Pranup Bhattarai,
Tushar Bhudia,
Aashish Chapagai,
Michael Huang,
Danyaal Kabir,
Vieran Khag,
Summyyah Khaliq,
Kush Khatri,
Jaidev Kneth,
Manisha Kothari,
Ibrahim Najmudin,
Lobanaa Panchalingam,
Manthan Patel,
Luxshan Premachandran,
Adam Qayyum,
Prasen Rana,
Zain Shaikh,
Sheryar Syed
, et al. (38 additional authors not shown)
Abstract:
We report follow-up observations of transiting exoplanets that have either large uncertainties (>10 minutes) in their transit times or have not been observed for over three years. A fully robotic ground-based telescope network, observations from citizen astronomers and data from TESS have been used to study eight planets, refining their ephemeris and orbital data. Such follow-up observations are k…
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We report follow-up observations of transiting exoplanets that have either large uncertainties (>10 minutes) in their transit times or have not been observed for over three years. A fully robotic ground-based telescope network, observations from citizen astronomers and data from TESS have been used to study eight planets, refining their ephemeris and orbital data. Such follow-up observations are key for ensuring accurate transit times for upcoming ground and space-based telescopes which may seek to characterise the atmospheres of these planets. We find deviations from the expected transit time for all planets, with transits occurring outside the 1 sigma uncertainties for seven planets. Using the newly acquired observations, we subsequently refine their periods and reduce the current predicted ephemeris uncertainties to 0.28 - 4.01 minutes. A significant portion of this work has been completed by students at two high schools in London as part of the Original Research By Young Twinkle Students (ORBYTS) programme.
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Submitted 4 May, 2020;
originally announced May 2020.