The physical properties of ThCr2Si2- type nickel-based superconductors BaNi2T2 (T = P, As): An ab-initio study

Abstract

Employing the first-principles computations based on the density functional theory (DFT), we have investigated the structural, mechanical, electronic, bonding, optical and thermodynamics properties of newly discovered bulk superconductors BaNi 2 P 2 (T c ~3 K) and BaNi 2 As 2 (T c ~0.7 K). Our optimized lattice parameters are in good concurrence with the experimental records. The positive elastic constants reveal that both the superconductors are stable in nature. The analysis of the mechanical properties insures that both the phases are ductile in nature and show anisotropic behaviors. The analysis of the electronic band structures and density of states (TDOS and PDOS) reveals the metallic manners for both the compounds and the major contribution comes from Ni-3d states for both the phases. The calculations of the chemical bonding specify that a mixture of covalent, ionic and metallic bonds exist in both the superconductors. The high value of the dielectric constant of BaNi 2 As 2 ensures that this compound may be used to manufacture high value capacitors. The large reflectivity in the low energy region indicates that both the compounds might be useful as coating materials to reduce solar heating. By using the elastic constants data the calculated Debye temperatures of BaNi 2 P 2 and BaNi 2 As 2 are 323.70 K and 272.94 K respectively, which are in good accordance with the experimental values. Finally we have calculated the thermal conductivity of these compounds which is 0.56 for BaNi 2 P 2 and 0.46 for BaNi 2 As 2 .

First-principles study of physical, and superconducting properties of newly discovered full-Heusler compound MgPd 2 Sb

“…however, for ionic bonding, the value of ν is 0.25 or more. Conversely, for the central force, the value of ν is 0.25<ν<0.50 [52,53]. Therefore, the MgPd 2 Sbsuperconductor possesses a central force because the value of ν is 0.3728.…”

CRYSTAL STRUCTURE OF THE PHOSPHIDES RPd2P2 (R = Gd, Tb, Dy, AND Er)

“…Найбільше сполук, які кристалізуються у цій тетрагональній структурі, виявлено у системах з силіцієм, германієм і бором, їх налічується понад 300, багато з них мають низку цікавих фізичних властивостей, зокрема про такі дослідження повідомляють у працях [4][5][6][7][8]. Не поступаються кількістю сполук із такою структурою і системи з фосфором, арсеном та стибієм [9][10][11][12]. Відомо, що така кристалічна структура є надструктурою другого роду до типу BaAl 4 , яка утворюється внаслідок упорядкованого розташування усіх сортів атомів у правильних системах точок просторової групи I4/mmm.…”

Optoelectronic, thermodynamic and vibrational properties of intermetallic MgAl2Ge2: a first-principles study

“…Among the AM 2 X 2 compounds, ThCr 2 Si 2 -type and CaCr 2 Si 2 -type structured materials have been investigated thoroughly in the field of high-T c superconductivity [12][13][14][15][16][17], the most common being the ternary pnictides [18]. The most surprising behaviors of pnictides are that they tend to be antiferromagnetic [19], and superconductivity emerges with doping or under high pressures [18].…”