Physics Commons^™

Stability Of Non-Centrosymmetric Phases In Tetra-Coordinated Of Ldtm Intercalates, A. S. Shkvarin, M.S. Postnikov, S. V. Pryanichnikov, A. N. Titov

Eurasian Journal of Physics and Functional Materials

On the basis of comparison of temperature dependences of lattice parameters of CuCrSe₂ and Cu_0.5ZrSe₂ in the temperature region including transition between phases with centrosymmetric and noncentrosymmetric distribution of copper on positions tetrahedrally coordinated by selenium. It is concluded that the critical factor that ensures the stability of the non- centrosymmetric copper distribution is the covalent interaction between copper and selenium sublattices. This effect is not related to the anisotropy of the elastic constants of the lattice and can be observed in other layered structures with copper tetrahedrally coordinated by chalcogen.

Study Of Static And Dynamical Properties Of Complex Antiferroelectrics Materials, Kinnary Yogeshbhai Patel

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of the static and dynamical properties of the complex antiferroelectric materials using Effective Hamiltonian method and First principles calculations. In chapter 3, a novel elemental interatomic coupling in perovskite materials which bilinearly couples the antiferroelectric displacements of cations with the rotations of the oxygen octahedra. This new coupling explains a very complex crystal structure of prototypical antiferroelectric PbZrO3. My explanation provides a unified description of many other complex antipolar crystal structures in variety of perovskite materials, including the occurrence of incommensurate phases in some of them. In chapter 4, results and analysis …

Static And Dynamical Properties Of Multiferroics, Sayed Omid Sayedaghaee

Graduate Theses and Dissertations

Since the silicon industrial revolution in the 1950s, a lot of effort was dedicated to the research and development activities focused on material and solid-state sciences. As a result, several cutting-edge technologies are emerging including the applications of functional materials in the design and enhancement of novel devices such as sensors, highly capable data storage media, actuators, transducers, and several other types of electronic tools. In the last two decades, a class of functional materials known as multiferroics has captured significant attention because of providing a huge potential for new designs due to possessing multiple ferroic order parameters at the …

First-Principles Simulations Of Materials Under Extreme Conditions, Kien Nguyen Cong

USF Tampa Graduate Theses and Dissertations

The investigation of materials at extreme conditions of high pressure and temperature (high-PT), has been one of the greatest scientific endeavors in condensed mater physics, chemistry, astronomy, planetary, and material sciences. Being subjected to high-PT conditions, materials exhibit dramatic changes in both atomic and electronic structure resulting in an emergence of exceptionally interesting phenomena including structural and electronic phase transitions, chemical reactions, and formation of novel compounds with never-previously observed physical and chemical properties. Although new exciting experimental developments in static and dynamic compression combined with new diagnostics/characterization methods allow to uncover new processes and phenomena at high P-T conditions, …

Structural Studies To Determine The Mechanisms Supporting Multiferroic And Ferroelectric Properties Of Complex Oxides, Han Zhang

Dissertations

Multiferroics are a class of materials which possess both magnetic and electrical polarization with possible coupling between them. They show promise to enable new sensors and data storage devices with novel features, such as the possibility of writing polarization bits with magnetic fields at low power. The coexisting magnetic and ferroelectric order parameters are usually weakly coupled, preventing practical use. The development and study of new classes of materials with large magnetoelectric couplings is of high importance. Understanding the structure of these materials is key to this effort.

As one class of these systems, the RX3(BO₃)₄ has …

Temperature Dependent Hadronic Bag And Qgp Phase Transition In Dual Qcd, G. Punetha, H. C. Chandola

Eurasian Journal of Physics and Functional Materials

Based on the magnetic symmetry structure of non-Abelian gauge theories, a dual QCD gauge theory has been constructed which takes into account the local structure as well as the topological features of the color gauge group into its dynamics in a completely dual-symmetric way. Using such dual version of QCD in thermal domain following the partition function approach and the grand canonical ensemble formulation, the phase transition from hadron to QGP phase has been investigated within the framework of temperature dependent hadronic bag in the entire T - μ plane. The various thermodynamic properties like pressure, energy density, speed of …

Quark-Hadron Phase Transition Study In Hadron-Nucleus Interactions In Self-Affine Scaling Scenario, S. Pal

Eurasian Journal of Physics and Functional Materials

In the present work the phase transition and its dependence on target excitation has been studied in two dimensional (η-φ) self affine space using the experimental data of pions obtained from π^- -AgBr interactions at 350 GeV/c. For studying target excitation dependence the data for produced pions are divided into three sets depending on the number of grey particles (n_g). The different sets corresponds to the different degrees of target excitation. The Levy indices μ measured from the analysis fulfills the requirement of the levy stable region 0 ≤ μ ≤ 2 . The Levy index μ …