Adsorption energy scaling relation on bimetallic magnetic surfaces: role of surface magnetic moments

2020 ◽  
Vol 22 (32) ◽  
pp. 17960-17968
Author(s):  
Swetarekha Ram ◽  
Seung-Cheol Lee ◽  
Satadeep Bhattacharjee
Keyword(s):  
Adsorption Energy ◽  
Magnetic Moments ◽  
Linear Scaling ◽  
Scaling Relation ◽  
Energy Scaling ◽  
Magnetic Surfaces ◽  
Adsorption Energies

Linear scaling of adsorption energies in terms of surface magnetic moments.

scholarly journals How covalence breaks adsorption-energy scaling relations and solvation restores them

2017 ◽  
Vol 8 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Federico Calle-Vallejo ◽  
Alexander Krabbe ◽  
Juan M. García-Lastra
Keyword(s):  
Aqueous Solution ◽  
Oxygen Reduction ◽  
Adsorption Energy ◽  
Scaling Relations ◽  
Scaling Relation ◽  
Energy Scaling ◽  
Adsorption Energies

We show that under vacuum various metalloporphyrins break the scaling relation between the adsorption energies of *OH and *OOH, which can potentially boost oxygen reduction and evolution. In aqueous solution, however, such scaling relation is restored.

scholarly journals Does the breaking of adsorption-energy scaling relations guarantee enhanced electrocatalysis?

2018 ◽  
Vol 8 ◽  
pp. 110-117 ◽  
Author(s):  
Nitish Govindarajan ◽  
Juan M. García-Lastra ◽  
Evert Jan Meijer ◽  
Federico Calle-Vallejo
Keyword(s):  
Adsorption Energy ◽  
Scaling Relations ◽  
Energy Scaling

scholarly journals Modified Dual-Site Langmuir Adsorption Equilibrium Models from A GCMC Molecular Simulation

2020 ◽  
Vol 10 (4) ◽  
pp. 1311
Author(s):  
Junchao Wang ◽  
Yongjie Wei ◽  
Zhengfei Ma
Keyword(s):  
Molecular Simulation ◽  
Adsorption Energy ◽  
Pressure Swing Adsorption ◽  
Adsorption Equilibrium ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Adsorption Energies ◽  
Pressure Swing ◽  
Adsorption Equilibrium Data ◽  
Dual Site

In the modern industrial separation process, the pressure swing adsorption technology is widely used to separate and purify gases due to its low energy consumption, low cost, convenience, reliability, and environmental benignity. The basic elements of the design and application of the pressure swing adsorption process are adsorption isotherms at different temperatures for adsorbents. The dual-site Langmuir (DSL) adsorption equilibrium model is the mostly used model; however, this model is based on the assumption that the adsorption energy on the surface of an adsorbent is uniform and remains unchanged. Here, a grand canonical Monte Carlo (GCMC) molecular simulation was used to calculate the CO2 adsorption equilibrium on MIL-101 (Cr) at 298 K. MIL-101 (Cr) was chosen, as it has more a general pore structure with three different pores. The calculation results showed that the adsorption energies with different adsorption pressures fitted a normal distribution and the relationship of the average adsorption energies, E with pressures had a linear form described as: E = aP + c. With this relationship, the parameter b = k·exp(E/RT) in the DSL model was modified to b = k·exp((aP + c)/RT), and the modified DSL model (M-DSL) was used to correlate the adsorption equilibrium data on CO2-MIL-101 (Cr), C2H4-HHPAC, CH4-BPL, and CO2-H-Mordenite, showing better correlations than those of the DSL model. We also extended the parameter qm in the M-DSL model with the equation qm = k1 + k2T to adsorption equilibrium data for different temperatures. The obtained model (M-TDSL) was checked with the abovementioned adsorption equilibrium systems. The fitting results also indicated that the M-TDSL model could be used to improve the correlation of adsorption equilibrium data for different temperatures. The linear relationship between the average adsorption energy and adsorption pressure could be further tested in other adsorption equilibrium models to determine its universality.

The Thermal Conductivity of Earth's Core: A Key Geophysical Parameter's Constraints and Uncertainties

2018 ◽  
Vol 46 (1) ◽  
pp. 47-66 ◽  
Author(s):  
Q. Williams
Keyword(s):  
Thermal Conductivity ◽  
High Pressures ◽  
Inner Core ◽  
Thermal Evolution ◽  
Magnetic Moments ◽  
Earth’S Core ◽  
Earth's Core ◽  
Current State ◽  
Core Conditions

The thermal conductivity of iron alloys at high pressures and temperatures is a critical parameter in governing ( a) the present-day heat flow out of Earth's core, ( b) the inferred age of Earth's inner core, and ( c) the thermal evolution of Earth's core and lowermost mantle. It is, however, one of the least well-constrained important geophysical parameters, with current estimates for end-member iron under core-mantle boundary conditions varying by about a factor of 6. Here, the current state of calculations, measurements, and inferences that constrain thermal conductivity at core conditions are reviewed. The applicability of the Wiedemann-Franz law, commonly used to convert electrical resistivity data to thermal conductivity data, is probed: Here, whether the constant of proportionality, the Lorenz number, is constant at extreme conditions is of vital importance. Electron-electron inelastic scattering and increases in Fermi-liquid-like behavior may cause uncertainties in thermal conductivities derived from both first-principles-associated calculations and electrical conductivity measurements. Additional uncertainties include the role of alloying constituents and local magnetic moments of iron in modulating the thermal conductivity. Thus, uncertainties in thermal conductivity remain pervasive, and hence a broad range of core heat flows and inner core ages appear to remain plausible.

scholarly journals Generalized Independence in the q-Voter Model: How Do Parameters Influence the Phase Transition?

Entropy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 120 ◽  
Author(s):  
Angelika Abramiuk ◽  
Katarzyna Sznajd-Weron
Keyword(s):  
Phase Transition ◽  
Critical Point ◽  
Broad Spectrum ◽  
Order Parameter ◽  
Analytical Formula ◽  
Voter Model ◽  
Pair Approximation ◽  
Scaling Relation ◽  
Independent Behavior

We study the q-voter model with flexibility, which allows for describing a broad spectrum of independence from zealots, inflexibility, or stubbornness through noisy voters to self-anticonformity. Analyzing the model within the pair approximation allows us to derive the analytical formula for the critical point, below which an ordered (agreement) phase is stable. We determine the role of flexibility, which can be understood as an amount of variability associated with an independent behavior, as well as the role of the average network degree in shaping the character of the phase transition. We check the existence of the scaling relation, which previously was derived for the Sznajd model. We show that the scaling is universal, in a sense that it does not depend neither on the size of the group of influence nor on the average network degree. Analyzing the model in terms of the rescaled parameter, we determine the critical point, the jump of the order parameter, as well as the width of the hysteresis as a function of the average network degree ⟨ k ⟩ and the size of the group of influence q.

scholarly journals INTERPLANETARY PROPAGATION OF SOLAR ENERGETIC PARTICLE HEAVY IONS OBSERVED AT 1 AU AND THE ROLE OF ENERGY SCALING

2012 ◽  
Vol 761 (2) ◽  
pp. 104 ◽  
Author(s):  
G. M. Mason ◽  
G. Li ◽  
C. M. S. Cohen ◽  
M. I. Desai ◽  
D. K. Haggerty ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Energy Scaling ◽  
Interplanetary Propagation

Electronic and Magnetic Properties of Ternary Stannides RERhSn (RE = Tb, Dy and Ho)

2011 ◽  
Vol 170 ◽  
pp. 74-77 ◽  
Author(s):  
Kazimierz Łątka ◽  
Jacek Gurgul ◽  
Andrzej W. Pacyna ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Properties ◽  
Electric Field ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Magnetic Studies ◽  
Crystalline Electric Field ◽  
Electric Field Effects ◽  
Electronic And Magnetic Properties ◽  
Field Effects

The results of magnetic studies and Mössbauer investigations made with 119Sn source are reviewed for the series of RERhSn (RE = Tb, Dy and Ho) compounds crystallizing in the same hexagonal ZrNiAl-type of structure. The role of crystalline electric field effects in the establishing of magnetic moment orientations observed in these compounds and their influence on the observed magnitudes of magnetic moments are discussed.

Sign in / Sign up

Export Citation Format

Share Document