Effect of shear strain on the deflection of a clamped magnetostrictive film–substrate system

2011 ◽  
Vol 323 (24) ◽  
pp. 3251-3258 ◽  
Author(s):  
Zheng Hui Ming ◽  
Li Ming ◽  
Zou Bo ◽  
Luo Xia
Keyword(s):  
Shear Strain ◽  
Film Substrate ◽  
Magnetostrictive Film

Role of Shear Strain for a General Modeling of Magnetostrictive Film-Substrate System

2011 ◽  
Vol 295-297 ◽  
pp. 1834-1842
Author(s):  
Ming Li ◽  
Hui Ming Zheng
Keyword(s):  
Shear Strain ◽  
Thick Film ◽  
Present Model ◽  
Type System ◽  
Substrate Plate ◽  
Film Substrate ◽  
Magnetostrictive Film ◽  
Plate Type ◽  
General Method

An approximate approach was presented to investigate the role of shear strain in calculation deflection of a magnetostrictive thick film-substrate plate-type system. Under provided assumptions, the present model can be reduced as the previous models including thin film,long thick film with both free ends.The obtained results shows shear strain plays an important role in calculation for short and wide cantilever specimen. It is also confirmed that the present model provides a general method of calculating deflection of a film-substrate cantilever system.

A More Exact Model for Predicting the Deflection of a Clamped Magnetostrictive Film-Substrate System

2011 ◽  
Vol 197-198 ◽  
pp. 552-557
Author(s):  
Ming Li
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Shear Strain ◽  
Strain Energy ◽  
Analytical Formula ◽  
Finite Element Package ◽  
Film Substrate ◽  
Shear Strain Energy ◽  
Magnetostrictive Film

A more exact general analytical formula of preditcting the magnetostrictive coefficient is derived for any aspect ratio based the deflection difference between the x and y directions. The curvatures are found by minimizing the total energy of the system, which taking into account shear strain energy. The in-plane stress distribution including shear stress for short specimen is also given by the ANSYS® finite element package to illustrate the role of shear strain in the deformation of magnetostrictive film-substrate system.

A Profound Discussion of the Inconsistencies in a Clamped Magnetostrictive Film-Substrate System

2011 ◽  
Vol 99-100 ◽  
pp. 100-105
Author(s):  
Ming Li ◽  
Hui Ming Zheng
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Mechanical Force ◽  
Normal Stresses ◽  
Magnetostrictive Materials ◽  
Film Substrate ◽  
Magnetostrictive Film

Recently, the inconsistencies are pointed out by previous authors for the problem of finding the strains, stresses and energy densities observed in isotropic elastic magnetostrictive materials that are in the form of thin films deposited on non-magnetic substrates. We discuss the reason of such inconsistencies that the total normal stresses should be the sum of the stresses caused by the external mechanical force and magnetic field. We show that such a situation can be realized in many of the current models used to make predictions for magnetostrictive structures and the inconsistencies can be explained.

Microtomy of spherical Al2O3 powders

1983 ◽  
Vol 41 ◽  
pp. 74-75
Author(s):  
E.J. Jenkins ◽  
D.S. Tucker ◽  
J.J. Hren
Keyword(s):  
Thin Film ◽  
Size Range ◽  
Particle Aggregation ◽  
Ion Milling ◽  
Thin Sections ◽  
Α Phase ◽  
Convenient Means ◽  
Van Der Waals Attraction ◽  
Negative Feature ◽  
Film Substrate

The size range of mineral and ceramic particles of one to a few microns is awkward to prepare for examination by TEM. Electrons can be transmitted through smaller particles directly and larger particles can be thinned by crushing and dispersion onto a substrate or by embedding in a film followed by ion milling. Attempts at dispersion onto a thin film substrate often result in particle aggregation by van der Waals attraction. In the present work we studied 1-10 μm diameter Al2O3 spheres which were transformed from the amprphous state to the stable α phase.After the appropriate heat treatment, the spherical powders were embedded in as high a density as practicable in a hard EPON, and then microtomed into thin sections. There are several advantages to this method. Obviously, this is a rapid and convenient means to study the microstructure of serial slices. EDS, ELS, and diffraction studies are also considerably more informative. Furthermore, confidence in sampling reliability is considerably enhanced. The major negative feature is some distortion of the microstructure inherent to the microtoming operation; however, this appears to have been surprisingly small. The details of the method and some typical results follow.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

Microstructural investigation of surface roughness in MBE-grown AlAs

1995 ◽  
Vol 53 ◽  
pp. 454-455
Author(s):  
R. Rajesh ◽  
R. Droopad ◽  
C. H. Kuo ◽  
R. W. Carpenter ◽  
G. N. Maracas
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Growth Control ◽  
Native Oxide ◽  
Effusion Cell ◽  
Surface Oxide Layer ◽  
Microstructural Investigation ◽  
Mbe Growth ◽  
Film Substrate ◽  
And Control

Knowledge of material pseudodielectric functions at MBE growth temperatures is essential for achieving in-situ, real time growth control. This allows us to accurately monitor and control thicknesses of the layers during growth. Undesired effusion cell temperature fluctuations during growth can thus be compensated for in real-time by spectroscopic ellipsometry. The accuracy in determining pseudodielectric functions is increased if one does not require applying a structure model to correct for the presence of an unknown surface layer such as a native oxide. Performing these measurements in an MBE reactor on as-grown material gives us this advantage. Thus, a simple three phase model (vacuum/thin film/substrate) can be used to obtain thin film data without uncertainties arising from a surface oxide layer of unknown composition and temperature dependence.In this study, we obtain the pseudodielectric functions of MBE-grown AlAs from growth temperature (650°C) to room temperature (30°C). The profile of the wavelength-dependent function from the ellipsometry data indicated a rough surface after growth of 0.5 μm of AlAs at a substrate temperature of 600°C, which is typical for MBE-growth of GaAs.

Sign in / Sign up

Export Citation Format

Share Document