TAILIEUCHUNG - Application of path integral for studying exafs cumulants

In this work, the path-integral effective potential (PIEP) method has been applied to re-study the temperature dependence of extended X-ray absorption fine structure (EXAFS) cumulants of materials. Using the trial density matrix and effective potential expression, we derived the analytical expressions of the first three EXAFS cumulants in the first shell of materials. The cumulant relation is also calculated to determine the temperature range in which the PIEP method could be applied. Our results are compared with available experimental data as well as with those calculated by the first-order perturbation approach in anharmonic Einstein model and the reasonable agreements are achieved. | Communications in Physics, Vol. 24, No. 3S1 (2014), pp. 40-44 DOI: APPLICATION OF PATH-INTEGRAL FOR STUDYING EXAFS CUMULANTS HO KHAC HIEU Duy Tan University, Da Nang, Viet Nam NGUYEN MANH HAI Hanoi University of Science, Vietnam National University, Hanoi E-mail: hieuhk@ Received 04 April 2014 Accepted for publication 24 May 2014 Abstract. In this work, the path-integral effective potential (PIEP) method has been applied to re-study the temperature dependence of extended X-ray absorption fine structure (EXAFS) cumulants of materials. Using the trial density matrix and effective potential expression, we derived the analytical expressions of the first three EXAFS cumulants in the first shell of materials. The cumulant relation is also calculated to determine the temperature range in which the PIEP method could be applied. Our results are compared with available experimental data as well as with those calculated by the first-order perturbation approach in anharmonic Einstein model and the reasonable agreements are achieved. Keywords: EXAFS cumulants, path-integral, effective potential. I. INTRODUCTION On the determination of the local structures of materials, the extended X-ray Absorption Fine Structure (EXAFS) spectroscopy is one of powerful techniques. The EXAFS data can be theoretically analyzed by means of the cumulant expansion method [1]. There are several approaches used to study the temperature dependence of anharmonic EXAFS cumulants such as perturbation approach in Einstein model [2] and Debye model [3], and statistical moment method [4]. However, most of these methods still can not be valid at very high temperature due to the strong anharmonic contributions. Recently, the path-integral effective potential (PIEP) method has been efficiently used to theoretically study thermodynamic properties of materials [5–8]. This method has included the anharmonic contributions as well as the quantum effects. In present .

• Vật lý
• Communications in Physics
• Application of path integral for studying exafs cumulants
• Studying exafs cumulants
• The path integral effective potential
• Extended X ray absorption fine structure
• Challenges in particle physics and 3 3 1 models
• Particle physics and 3 3 1 models
• Particle theory and field theory models
• The early Universe
• Non standard model neutrino
• The 3 3 1 models in current particle physics
• Current particle physics
• The Standard Model
• The electro weak
• The process of e+e − → µ +µ
• The randall sundrum model
• Supersymmetric model and unparticle physics
• Randall Sundrum model
• Supersymmetric and Unparticle physics
• Handbook of mechanical engineering
• mechanical engineering
• mechanical design
• mechanical materials
• alloy materials
• Energy Technology
• Compact device model for nanoparticle organic memory transistor’s characterization
• Nanoparticle organic memory transistor
• Hybrid integrated circuit
• Hybrid NOMFET CMOS neuromorphic computing circuit
• Microdroplet in T junction microfluidic system
• Experiment and simulation
• T junction microfluidic system
• Lateral channel decrease
• Optical bistability in three level eit configurations
• Three level eit configurations
• Effects of atomic coherence
• OB in V type system
• Dynamical codimension 2 brane
• Warped six dimensional space time
• Codimension 2 brane
• Warped 6D bulk space time
• Coherent diffractive imaging using table top high harmonic generation
• Coherent diffractive imaging
• Table top high harmonic generation
• Growth of single crystals of methylammonium lead mixedhalide perovskites
• Growth of single crystals
• Methylammonium lead mixedhalide perovskites
• Organo lead mixed halide perovskites
• Tuning electronic transport properties
• Zigzag graphene nanoribbons
• Stone wales defect
• Negative differential resistance
• Asymmetric and symmetric ZGNRs
• The transmembrane italian mutant
• The temperature replica exchange molecular dynamics
• TmE22K trimer structure
• Kinetics probably yield
• Electrochemical fabrication of hybrid plasmonic dielectric nanomaterials
• Gold diamond clusters
• Hybrid plasmonic dielectric nanomaterials
• hybrid plasmonic dielectric materials
• Electron microscopy and optical characterization
• X ray absorption fine structure
• BCC crystals studied
• High order expanded debye waller factors
• Debye Waller factors
• Temperature dependent cumulants
• Nonlinear optics in waveguide arrays and photonic nanowires
• Nonlinear optics in waveguide arrays
• Diffractive resonant radiation
• The spectral body of the pulse
• Radion production in high energy photon collisions
• Solve the hierarchy problem
• Energy loss function for lead
• Local field effect
• Adiabatic local density approximation
• First principles calculations shows good agreemen
• Perturbative nonlinear optics in the extreme ultraviolet region
• The extreme ultraviolet region
• Different extreme ultraviole
• Multiple cycle pulses
• Thermodynamic hadron quark phase transition
• Chiral nuclear matter to quark gluon plasma
• Quark gluon plasma
• Equilibrium properties near critical points
• Phase transitions and critical phenomena
• Chirality of light in hybrid modes
• Vacuum clad ultrathin optical fibers
• Ultrathin optical fibers
• Superchiral outside the fiber
• An advanced logarithmic phase mask for extending depth
• Field of hybrid optical systems
• Modulation transfer functions
• Hybrid imaging system
• Hyperon W production in pp collisions at energy 8 tev
• Investigate the hadronization process
• The RICH detector
• The nominal value
• Profile of the 12co(3 2) emission line detected
• The debris disc of 49 ceti
• Require relatively violent
• Generate secondary gas
• Synthesis and optical characterization
• Building block plasmonic gold nanostructures
• Random nano islands
• Random Au nano islands
• Electrochemical performance of Na0
• 44Mno2 synthesized
• Hydrothermal method using as a cathode material
• Sodium ion batteries
• Sodium ion battery
• Stable during cycling