scholarly journals High-Pressure Structures and Superconductivity of Barium Iodide

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 522
Author(s):  
Shubo Wei ◽  
Hanyu Liu

Generally, pressure is a useful tool to modify the behavior of physical properties of materials due to the change in distance between atoms or molecules in the lattice. Barium iodide (BaI2), as one of the simplest and most prototypical iodine compounds, has substantial high pressure investigation value. In this work, we explored the crystal structures of BaI2 at a wide pressure range of 0–200 GPa using a global structure search methodology. A thermodynamical structure with tetragonal I4/mmm symmetry of BaI2 was predicted to be stable at 17.1 GPa. Further electronic calculations indicated that I4/mmm BaI2 exhibits the metallic feature via an indirect band gap closure under moderate pressure. We also found that the superconductivity of BaI2 at 30 GPa is much lower than that of CsI at 180 GPa based on our electron–phonon coupling simulations. Our current simulations provide a step toward the further understanding of the high-pressure behavior of iodine compounds at extreme conditions.

Vacuum ◽  
2017 ◽  
Vol 145 ◽  
pp. 123-127 ◽  
Author(s):  
Yanwu Li ◽  
Yongjun Cheng ◽  
Wenjun Sun ◽  
Yongjun Wang ◽  
Meng Dong ◽  
...  

Adsorption ◽  
2015 ◽  
Vol 21 (1-2) ◽  
pp. 53-65 ◽  
Author(s):  
Yongchen Song ◽  
Wanli Xing ◽  
Yi Zhang ◽  
Weiwei Jian ◽  
Zhaoyan Liu ◽  
...  

2013 ◽  
Vol 313-314 ◽  
pp. 666-670 ◽  
Author(s):  
K.J. Suja ◽  
Bhanu Pratap Chaudhary ◽  
Rama Komaragiri

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.


2021 ◽  
pp. 2150386
Author(s):  
Shifeng Niu ◽  
Ran Liu ◽  
Xuhan Shi ◽  
Zhen Yao ◽  
Bingbing Liu ◽  
...  

The structural evolutionary behaviors of AgN3 have been studied by using the particle swarm optimization structure search method combined with the density functional theory. One stable high-pressure metal polymeric phase with the [Formula: see text] space group is suggested. The enthalpy difference analysis indicates that the Ibam-AgN3 phase will transfer to the I4/mcm-AgN3 phase at 4.7 GPa and then to the [Formula: see text]-AgN3 phase at 24 GPa. The [Formula: see text]-AgN3 structure is composed of armchair–antiarmchair N-chain, in which all the N atoms are sp2 hybridization. The inherent stability of the armchair–antiarmchair chain and the anion–cation interaction between the N-chain and Ag atom induce a high stability of the [Formula: see text]-AgN3 phase, which can be captured at ambient conditions and hold its stable structure up to 1400 K. The exhibited high energy density (1.88 KJ/g) and prominent detonation properties ([Formula: see text] Km/s; [Formula: see text] GPa) of the [Formula: see text]-AgN3 phase make it a potentially high energy density material.


Author(s):  
William Neil Morley ◽  
Shane Ferth ◽  
Mathew Ian Bergens Debenham ◽  
Matthew Boston ◽  
Geoffrey Alonzo Power ◽  
...  

Despite compelling muscular structure and function changes resulting from blood flow restricted (BFR) resistance training, mechanisms of action remain poorly characterized. Alterations in tissue O2 saturation (TSI%) and metabolites are potential drivers of observed changes, but their relationships with degree of occlusion pressure are unclear. We examined local TSI% and blood lactate (BL) concentration during BFR training to failure using different occlusion pressures on strength, hypertrophy, and muscular endurance over an 8-week training period. Twenty participants (11M:9F) trained 3/wk for 8wk using high pressure (100% resting limb occlusion pressure, LOP, 20%1RM), moderate pressure (50% LOP, 20%1RM), or traditional resistance training (70%1RM). Strength, size, and muscular endurance were measured pre/post training. TSI% and BL were quantified during a training session. Despite overall increases, no group preferentially increased strength, hypertrophy, or muscular endurance (p>0.05). Neither TSI% nor BL concentration differed between groups (p>0.05). Moderate pressure resulted in greater accumulated deoxygenation stress (TSI%*time) (-6352±3081, -3939±1835, -2532±1349 au for moderate pressure, high pressure, and TRT, p=0.018). We demonstrate that BFR training to task-failure elicits similar strength, hypertrophy, and muscular endurance changes to traditional resistance training. Further, varied occlusion pressure does not impact these outcomes, nor elicit changes in TSI% or BL concentrations. Novelty Bullets • Training to task failure with low-load blood flow restriction elicits similar improvements to traditional resistance training, regardless of occlusion pressure. • During blood flow restriction, altering occlusion pressure does not proportionally impact tissue O2 saturation nor blood lactate concentrations


1991 ◽  
Vol 46 (5) ◽  
pp. 653-661 ◽  
Author(s):  
Andreas Eggert ◽  
Erwin Riedel

FeCr2O4 has been prepared under CO-CO2-atmosphere with oxygen partial pressures between 10-18 and 10-8 bar. X-Ray and Mößbauer investigations show that under higher pressures FeCr2O4 is not stoichiometric but contains Fe(III), and that corund type Cr2O3 as an additional phase has been formed. In the wide pressure range from 10-17 to 10-14 bar the contents of Fe(III) are lower than 1% of total iron, and the corund phase is negligible.


2020 ◽  
Vol 12 (14) ◽  
pp. 16691-16699 ◽  
Author(s):  
Han Byul Choi ◽  
Jinwon Oh ◽  
Youngsoo Kim ◽  
Mikhail Pyatykh ◽  
Jun Chang Yang ◽  
...  

2020 ◽  
Vol 91 (11) ◽  
pp. 113501
Author(s):  
Ante Hecimovic ◽  
Federico D’Isa ◽  
Emile Carbone ◽  
Aleksander Drenik ◽  
Ursel Fantz

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