Mimicking very thin particulate coatings by employing a soft-magnetic underlayer

2000 ◽  
Vol 36 (5) ◽  
pp. 2429-2431 ◽  
Author(s):  
R.J. Veitch
Author(s):  
June D. Kim

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.


Author(s):  
John G. Sheehan

Improvements in particulate coatings for printable paper require understanding mechanisms of colloidal interactions in paper coating suspensions. One way to deduce colloidal interactions is to mage particle spacings and orientations at high resolution with cryo-SEM. Recent improvements in cryo-SEM technique have increased resolution enough to image particles in coating paints,vhich are sometimes smaller than 100 nm. In this report, a metal-coating chamber is described for preparation of colloidal suspensions for cryo-SEM at resolution down to 20 nm. It was found that etching is not necessary to achieve this resolution.A 120 K cryo-SEM sample will remain in an SEM for hours without noticeable condensation of imorphous ice. This is due to the high vapor pressure of vapor-condensed amorphous ice, measured by Kouchi. However, clean vacuum is required to coat samples with the thinnest possible continuous metal films which are required for high magnification SEM. Vapor contaminants, especially hrydrocarbons, are known to interfere with thin-film nucleation and growth so that more metal is needed to form continuous films, and resolution is decreased. That is why the metal-coating chamber in fig. 1 is designed for the cleanest possible vacuum. Feedthroughs for the manipulator md the shutter, which are operated during metal coating, are sealed with leak-proof stainless-steel Dellows. The transfer rod slides through a baseplate feedthrough that is double o-ring sealed.


1998 ◽  
Vol 22 (4_1) ◽  
pp. 186-189
Author(s):  
M. Matsumoto ◽  
A. Morisako ◽  
Y. Mutoh

2013 ◽  
Vol 133 (11) ◽  
pp. 1073-1081 ◽  
Author(s):  
Hirooki Tokoi ◽  
Kinya Kobayashi ◽  
Hideaki Nagashima ◽  
Shuichi Ishizawa ◽  
Yuji Enomoto

2019 ◽  
Vol 139 (10) ◽  
pp. 873-879 ◽  
Author(s):  
Tsuyoshi Nonaka ◽  
Shingo Zeze ◽  
Shogo Makino ◽  
Motomichi Ohto

2002 ◽  
Vol 93 (1) ◽  
pp. 21-27
Author(s):  
Á. Cziráki ◽  
I. Gerocs ◽  
L. K. Varga ◽  
I. Bakonyi ◽  
U. Falke ◽  
...  

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