Modeling of coupled proton transfers by analytic functions

Duan, Xiaofeng; Scheiner, Steve

doi:10.1002/qua.560440713

Cited by 12 publications

(9 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The motivation and the microscopic reasoning for this potential have been explained in detail in [16,32,47], to which the reader is referred. As the two-Morse potential takes into account the quantum chemistry considerations [49], its shape for an isolated single-particle is shown in figure 1 for various values of ad, where it appears that the potential actually has two minima if ad > ln (2). Therefore, if the splitting parameter d exceeds a certain critical value d c = ln(2)/a, it has two minima separated by a potential barrier V , so that the function V (Q, d) appears as two valleys separated by a potential hill.…”

Section: Model and Formalismmentioning

confidence: 99%

Thermodynamic properties of a quasi-harmonic model for ferroelectric transitions

Tchouobiap

Mashiyama

2011

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Within a framework of a quasi-harmonic model for quantum particles in a local potential of the double Morse type and within the mean-field approximation for interactions between particles, we investigate the thermodynamic properties of ferroelectric materials. A quantum thermodynamic treatment gives analytic expressions for the internal energy, the entropy, the specific heat, and the static susceptibility. The calculated thermodynamic characteristics are studied as a function of temperature and energy barrier, where it is shown that at the proper choice of the theory parameters, particularly the energy barrier, the model system exhibits characteristic features of either second-order tricritical or first-order phase transitions. Our results indicate that the barrier energy seems to be an important criterion for the character of the structural phase transition. The influence of quantum fluctuations manifested on zero-point energy on the phase transition and thermodynamic properties is analyzed and discussed. This leads to several quantum effects, including the existence of a saturation regime at low temperatures, where the order parameter saturates giving thermodynamic saturation of the calculated thermodynamic quantities. It is found that both quantum effects and energy barrier magnitude have an important influence on the thermodynamic properties of the ferroelectric materials and on driving the phase transition at low temperatures. Also, the analytical parameters' effect on the transition temperature is discussed, which seems to give a general insight into the structural phase transition and its nature.

show abstract

Section: Model and Formalismmentioning

confidence: 99%

Thermodynamic properties of a quasi-harmonic model for ferroelectric transitions

Tchouobiap

Mashiyama

2011

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…Various models based on the same idea [15,[18][19][20] have followed these pioneering works. These two Morse potentials have been introduced later by other authors in the context of soliton theories [21][22][23][24].…”

Section: Ii-the Polarizability Model Hamiltonianmentioning

confidence: 99%

“…Using equations (19) and (20), and considering that the variance at the critical point is found from (25)…”

Section: Iv-determination Of the Critical Ferroelectric Phase Transitmentioning

confidence: 99%

Self-Consistent Nonlinearly Polarizable Shell-Model Dynamics for Ferroelectric Materials

Tchouobiap¹,

Ngabireng²,

Kofané³

2004

Phys. Scr.

View full text Add to dashboard Cite

We investigate the dynamical properties of the polarizable shell-model with a symmetric double Morse-type electron-ion interaction in one ionic species. A variational calculation based on the Self-Consistent Einstein Model (SCEM) shows that a theoretical ferroelectric (FE) transition temperature can be derived which demonstrates the presence of a first-order phase transition for the potassium selenate (K 2 SeO 4 ) crystal around Tc = 91.5 K. Comparison of the model calculation with the experimental critical temperature yields satisfactory agreement.

show abstract

“…On the other hand, we do not discuss very much in this paper the numerical values for the parameters because they are discussed in many works ͑see, e.g., Refs. ͓10,12,16,24,[26][27][28][29] …”

Section: The Model For a Single Hydrogen Bondmentioning

confidence: 99%

Collective proton transport with weak proton-proton coupling

Zolotaryuk

Peyrard²,

Spatschek³

2000

Phys. Rev. E

View full text Add to dashboard Cite

A mechanism based on the peculiar dynamical properties of the hydrogen bond is suggested to describe fast proton transfers in hydrogen-bonded chains with realistic (weak) intersite proton-proton interactions. For this purpose, a two-sublattice model is suggested and studied analytically that admits an exact soliton solution. The solitons, which are topological objects (kinks and antikinks) on the one hand, but dynamical entities (like Boussinesq solitons) on the other hand, are shown to have a sufficiently large width to allow free propagation along the chain.

show abstract

Modeling of coupled proton transfers by analytic functions

Cited by 12 publications

References 40 publications

Thermodynamic properties of a quasi-harmonic model for ferroelectric transitions

Thermodynamic properties of a quasi-harmonic model for ferroelectric transitions

Self-Consistent Nonlinearly Polarizable Shell-Model Dynamics for Ferroelectric Materials

Collective proton transport with weak proton-proton coupling

Contact Info

Product

Resources

About