scholarly journals High-temperature superconductivity in layered nitridesβ-LixMNCl (M=Ti, Zr, Hf): Insights from density functional theory for superconductors

2012 ◽  
Vol 86 (5) ◽  
Author(s):  
Ryosuke Akashi ◽  
Kazuma Nakamura ◽  
Ryotaro Arita ◽  
Masatoshi Imada
Keyword(s):  
Density Functional Theory ◽  
High Temperature ◽  
Density Functional ◽  
High Temperature Superconductivity ◽  
Functional Theory

scholarly journals Higher superconducting transition temperature by breaking the universal pressure relation

2019 ◽  
Vol 116 (6) ◽  
pp. 2004-2008 ◽  
Author(s):  
Liangzi Deng ◽  
Yongping Zheng ◽  
Zheng Wu ◽  
Shuyuan Huyan ◽  
Hung-Cheng Wu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Temperature ◽  
Transition Temperature ◽  
Density Functional ◽  
High Temperature Superconductors ◽  
Density Functional Theory Calculations ◽  
Universal Relation ◽  
Superconducting Transition ◽  
Functional Theory ◽  
A Charge

By investigating the bulk superconducting state via dc magnetization measurements, we have discovered a common resurgence of the superconducting transition temperatures (Tcs) of the monolayer Bi2Sr2CuO6+δ(Bi2201) and bilayer Bi2Sr2CaCu2O8+δ(Bi2212) to beyond the maximum Tcs (Tc-maxs) predicted by the universal relation between Tcand doping (p) or pressure (P) at higher pressures. The Tcof underdoped Bi2201 initially increases from 9.6 K at ambient to a peak at 23 K at 26 GPa and then drops as expected from the universal Tc-P relation. However, at pressures above 40 GPa, Tcrises rapidly without any sign of saturation up to 30 K at 51 GPa. Similarly, the Tcfor the slightly overdoped Bi2212 increases after passing a broad valley between 20 and 36 GPa and reaches 90 K without any sign of saturation at 56 GPa. We have, therefore, attributed this Tcresurgence to a possible pressure-induced electronic transition in the cuprate compounds due to a charge transfer between the Cu 3dx2−y2and the O 2pbands projected from a hybrid bonding state, leading to an increase of the density of states at the Fermi level, in agreement with our density functional theory calculations. Similar Tc-P behavior has also been reported in the trilayer Br2Sr2Ca2Cu3O10+δ(Bi2223). These observations suggest that higher Tcs than those previously reported for the layered cuprate high-temperature superconductors can be achieved by breaking away from the universal Tc-P relation through the application of higher pressures.

scholarly journals Computational prediction of the thermoelectric performance of LaZnOPn (Pn = P, As)

2020 ◽  
Vol 8 (16) ◽  
pp. 7914-7924 ◽  
Author(s):  
Maud Einhorn ◽  
Benjamin A. D. Williamson ◽  
David O. Scanlon
Keyword(s):  
Density Functional Theory ◽  
High Temperature ◽  
Thermoelectric Materials ◽  
Density Functional ◽  
State Of The Art ◽  
Computational Prediction ◽  
Thermoelectric Performance ◽  
Functional Theory ◽  
Earth Abundant ◽  
P Type

State-of-the-art density functional theory is used to demonstrate that LaZnOP and LaZnOAs have great potential as earth-abundant p-type thermoelectric materials for high-temperature applications.

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