Relation between longitudinal and transverse strain coefficient of resistances in bulk metals and thin films

1973 ◽  
Vol 16 (2) ◽  
pp. K137-K141
Author(s):  
G. C. Jain ◽  
B. S. Verma
2020 ◽  
Vol 175 ◽  
pp. 03005
Author(s):  
Vladimir Khripin ◽  
Vyacheslav Ulyanov ◽  
Alexander Kiryanov ◽  
Ekaterina Kurochkina ◽  
Lyudmila Cherkashina

A rational technology for cows’ machine milking when tie-up housing should provide for the development of technical equipment that meets the physiological requirements for a dairy cow and ensure complete and safe milking. In this regard, the task of determining and refining certain parameters of the physical-mechanical characteristics of the mammary gland of a cow becomes urgent. When choosing the rational mass of the suspended part of the vacuum milking machine, one should know the pressure transmitted by the teat cup liner to the body of the nipple of the animal when milking, which makes possible to establish the obtained analytical formula. It was found that the higher the deflection of the walls of the stretched teat cup liner, the higher the pressure caused by it on the nipple of the cow’s udder. Analysis of the distribution of diameters and lengths of the nipples of the mammary gland of cows showed that their sizes vary in wide ranges. Elongations of nipples depend nonlinearly on the acting tension, and the values of the elastic modulus and the transverse strain coefficient vary over a wide range.


Author(s):  
Protsenko I. Yu ◽  
Odnodvorets L.V ◽  
Tyschenko K.V. ◽  
Shumakova M.O.

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 427
Author(s):  
Tongxin Nie ◽  
Baomin Wang ◽  
Bo Liu ◽  
Yali Xie ◽  
Huali Yang ◽  
...  

The wrinkling structures, which can greatly improve the stretchability of the metallic thin films, have been widely used in the preparation of stretchable devices. However, the artificial wrinkling structures are often accompanied by the generation of microcracks, which seriously affect the performance of the devices. In this work, by establishing the corresponding model, the transverse strain of the longitudinally prestrained continuous film and the strip film is mechanically analyzed, which is verified by experimental results; for the strain of blank substrate, the error of the model was about 3.7%. It is difficult to avoid the generation of microcracks with continuous films, but strip films can avoid the generation of microcracks to a certain extent. The experimental results illustrate the various factors affecting the generation of microcracks. The transverse strain of the film is proportional to the substrate’s Young’s modulus, Poisson’s ratio, thickness, and prestrain and is basically inversely proportional to the strip film’s Young’s modulus, thickness, and strip interval. Our results provide deeper knowledge for choosing proper metallic materials to fabricate stretchable wrinkled devices.


Author(s):  
L.J. Chen ◽  
Y.F. Hsieh

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.


Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.


Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.


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