Landau phenomenological model for the alpha-INC (incommensurate)-beta transition in quartz

2021-08-01
The temperature dependence of the order parameters eta (alpha-phase) and xi (INC - incommensurate phase) are calculated in the presence of the electric field for the alpha-INC-beta transition in quartz by the Landau mean field theory. Landau phenomenological model with the linear (eta xi) and quadratic (eta(2)xi(2)) coupling is introduced to investigate mainly the nature of the INC phase between alpha (ordered) and beta (disordered) phases in quartz. The temperature dependence of the inverse susceptibilities (chi(-1h)(eta) and chi(-1)(xi)) of the order parameter is also predicted at constant electric fields studied for the alpha-INC-beta transition in quartz. Additionally, the E-T phase diagram for the transitions of the alpha-INC and INC-beta in quartz is constructed from the Landau phenomenological model by using the literature data. Our predictions for the order parameters (eta and xi) and the inverse susceptibilities (chi(-1)(eta) and chi(-1)(xi)) can be compared with the experimental measurements for the alpha-INC-beta transition in quartz.
PHILOSOPHICAL MAGAZINE

Suggestions

Investigation of the incommensurate (INC) phase between α and β phases in quartz and related materials
Ateş, Simge; Yurtseven, Hasan Hamit; Department of Physics (2021-2-10)
Incommensurate (INC) phase as an intermediate sinusoidal phase which exists in anarrow temperature range (∼1.3◦C) between the low-temperatureαand the high-temperatureβphases in quartz, is investigated extensively. The phase transitions oftheα-INC and INC-βoccurring as first order and second order type, respectively,are studied using the experimental data from the literature. Order-disorder transi-tion between theαandβquartz through the incommensurate phase is described bytemperature and pressure dependen...
Landau mean-field model with the cubic term for the alpha-beta transition in quartz
Ates, S.; Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 2020-06-01)
Thermodynamic quantities are calculated as a function of temperature by using Landau mean-field model for the alpha-beta transition in quartz. By expanding the Gibbs free energy in terms of the order parameter (Q) with the cubic term (Q(3)), the temperature dependence of the relevant thermodynamic quantities are predicted using the heat capacity (C-P), which is fitted to the experimental data from the literature for the alpha-beta transition in quartz. Our results indicate that the Landau mean-field model i...
Spontaneous polarization close to phase transitions in NaNO2
Yurtseven, Hasan Hamit; Tari, O (2001-08-01)
We give here the calculation of the order parameter and the spontaneous polarization as functions of temperature using the mean field model close to the phase transitions in NaNO2. We have fitted our calculated order parameter to the observed one from the literature. From this fitting, we have then calculated the spontaneous polarization as a function of temperature close to the phase transitions in NaNO2. Our calculated spontaneous polarization is in good agreement with the observed spontaneous polarizatio...
Calculation of the P-T phase diagram of nitrogen using a mean field model
Enginer, Y.; Algul, G.; Yurtseven, Hasan Hamit (2017-12-20)
The P-T phase diagram is calculated at low and moderate pressures by obtaining the phase line equations for the transitions considered in nitrogen using the Landau phenomenological model. For some transitions, a quadratic coupling between the order parameters is taken into account in the expansion of free energies in terms of the order parameters. A quadratic function in T and P is fitted to the experimental P-T data from the literature and the fitted parameters are determined.
Generalized Shioda-Inose structures on K3 surfaces
Onsiper, H; Sertoz, S (Springer Science and Business Media LLC, 1999-04-01)
In this note, we study the action of finite groups of symplectic automorphisms on K3 surfaces which yield quotients birational to generalized Kummer surfaces. For each possible group, we determine the Picard number of the K3 surface admitting such an action and for singular K3 surfaces we show the uniqueness of the associated abelian surface.
Citation Formats
H. H. Yurtseven, “Landau phenomenological model for the alpha-INC (incommensurate)-beta transition in quartz,” PHILOSOPHICAL MAGAZINE, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/91944.