One‐dimensional energy barrier model for coercivity

1993 ◽  
Vol 73 (10) ◽  
pp. 6829-6831 ◽  
Author(s):  
James A. Jatau ◽  
Edward Della Torre
Keyword(s):  
Energy Barrier ◽  
One Dimensional ◽  
Barrier Model

scholarly journals An improved, stress-dependent, energy-barrier model for the creep of 9Cr-1Mo-0.2V steel under disc-bend loading

2010 ◽  
Vol 48 (4) ◽  
pp. 233-239
Author(s):  
A. NAGODE ◽  
B. ULE ◽  
L. KOSEC ◽  
M. JENKO
Keyword(s):  
Energy Barrier ◽  
Stress Dependent ◽  
Barrier Model

scholarly journals Extract and approximate expressions for the permeability of potential barriers to light particles

1937 ◽  
Vol 158 (893) ◽  
pp. 128-136 ◽  
Keyword(s):  
Schrödinger Equation ◽  
Energy Barrier ◽  
Schrodinger Equation ◽  
Potential Energy Function ◽  
Continuous Curve ◽  
Reaction Velocity ◽  
One Dimensional ◽  
Potential Barriers ◽  
The One ◽  
Approximate Expressions

In order to calculate the permeability of an energy barrier to a particle of mass m and energy W it is necessary to solve the Schrödinger equation for the potential energy function V ( x ) representing the barrier. An exact solution has only been obtained for one type of barrier represented by a continuous curve (which we shall call the Eckart barrier), and in this case the resulting expression for the permeability is an inconvenient one for application to problems of reaction velocity. Most treatments of this subject have therefore been based on the following approximate method. If the wave function is written in the form Ψ( x ) = e 8 ( x ) , the one-dimensional Schrödinger equation becomes d 2 s / dx 2 + ( ds / dx ) 2 + 8π 2 m / h 2 {W - V( x )} = 0. (1) This equation can be solved approximately provided that the first term is small compared with the second, i.e. , if | d 2 s / dx 2 / ( ds / dx ) 2 | ≪ 1.

Theory of Ionic Diffusion Across Material Interfaces

1992 ◽  
Vol 293 ◽  
Author(s):  
M. Balkanski ◽  
I. Nachev ◽  
J. Deppe ◽  
R. F. Wallis
Keyword(s):  
Energy Barrier ◽  
Lattice Gas ◽  
Lattice Gas Model ◽  
Ionic Diffusion ◽  
Intermediate Step ◽  
Material Interfaces ◽  
Linear Diffusion ◽  
Dimensional Lattice ◽  
One Dimensional ◽  
Self Consistent

AbstractIon diffusion across material interfaces is considered in a sequence of approximations with increasing complexity. First, the one-dimensional lattice gas model of particle diffusion is generalized to include a finite width interface region, and the possible existence of an energy barrier at the interface. Overvoltage measurements on InSe, and dielectric loss measurements on B2O3 - 0.5Li20 - 0.15Li2SO4 are used to determine the field-free hopping rates in the two materials. It is shown that the energy barrier is a dominant parameter. This model is then modified by considering the disorder of the glass structure and the blocking effect resulting from the ion interaction. Next, a more rigorous treatment is presented by solving the Poisson equation with appropriate boundatry conditions, and a self-consistent theory of the ionic diffusion is proposed. To clarify this problem, an intermediate step and two additional models with increasing sophistication are considered: first, the potential φ(x) of the moving charge density n(x) is calculated and it is shown that φ(x) is not negligible. Then, a feed-back is provided by including this potential in the diffusion equation. This treatment is already self-consistent and more realistic but leads to long computations even for the simple one dimensional lattice-gas model. A remedy of this difficulty is proposed whereby the theory is reformulated in order to guarantee from the beginning the self-consistency of the solution of the non-linear diffusion problem. Straightforward extensions to the two-dimensional case are then possible. The results of the computations are illustrated with numerical examples for different values of the physical parameters.

Magnetic and Optical Properties of Novel Lanthanide(III) Complexes Based on Schiff Base and β-Diketonate Ligands

2018 ◽  
Vol 71 (7) ◽  
pp. 527
Author(s):  
Yufeng Jia ◽  
Hongfeng Li ◽  
Peng Chen ◽  
Ting Gao ◽  
Wenbin Sun ◽  
...  
Keyword(s):  
Optical Properties ◽  
Schiff Base ◽  
Solid State ◽  
Single Molecule ◽  
Energy Barrier ◽  
Quantum Yields ◽  
Single Molecule Magnet ◽  
One Dimensional ◽  
Self Assembling ◽  
Magnetic Analysis

A series of lanthanide-based self-assembling complexes constructed from Schiff base and β-diketonate ligands have been synthesised by the same method. They are one dimensional complexes ({[Ln(H2L)(tta)2(OAc)]·0.5H2O}n (Ln = Eu (1), Gd (2), Dy (3), Yb (4)); H2L = N,N′-bis(salicylidene)butane-1,4-diamine, tta = 2-thenoyltrifluoroacetone). Complexes 1 and 4 exhibit characteristic metal-centred emission in the solid state. The lifetimes and quantum yields of luminescence were also determined. Magnetic analysis reveals that complex 3 exhibits field-induced single-molecule magnet (SMM) behaviour with an energy barrier of 24.07 K.

Optical Properties and Photoexcitations in Regularly Alternating Conjugated Copolymers

1993 ◽  
Vol 328 ◽  
Author(s):  
R. Tubino ◽  
C. Botta ◽  
S. Destri ◽  
W. Porzio ◽  
L. Rossi
Keyword(s):  
Conjugated Polymers ◽  
Energy Barrier ◽  
Lattice Distortion ◽  
Emission Spectra ◽  
Optical Characterization ◽  
Short Paper ◽  
One Dimensional ◽  
Preliminary Account ◽  
Thiophene Moiety ◽  
Resonant Raman

ABSTRACTWe report in this short paper a preliminary account on the design, preparation, optical characterization and photoexcitation of a class of novel conjugated polymers consisting of regularly alternating thiophene and benzene sequences, which Might represent Models for one-dimensional superlattices. Optical absorption and emission spectra suggest that the barriers produced by the phenylene Moieties do not interrupt the conjugation but can produce localization effects. Resonant Raman spectra indicate that a selective response of the thiophene Moiety occurs upon excitation with visible light. Moreover these Measurements confirm the presence of a confinement on the thiophene blocks, while the biphenil Moiety does not appear to feel the energy barrier and behaves as the corresponding polymer poly (paraphenylene) (PPP). CW photomodulation spectra show that the formation of long-lived bipolarons takes place only if the thienylenic Moiety is long enough to accomodate the lattice distortion.

One-dimensional cobalt(ii) coordination polymer featuring single-ion-magnet-type field-induced slow magnetic relaxation

2018 ◽  
Vol 42 (12) ◽  
pp. 9612-9619 ◽  
Author(s):  
Xiangyu Liu ◽  
Xiufang Ma ◽  
Peipei Cen ◽  
Fengqing An ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Easy Axis ◽  
One Dimensional ◽  
Slow Magnetic Relaxation

Single-ion-magnet-type field-induced double magnetic relaxation was observed in a one-dimensional cobalt(ii) coordination polymer which shows easy-axis anisotropy with D = −33.9 cm−1 and an energy barrier of Ueff = 38.8 K.

Sign in / Sign up

Export Citation Format

Share Document