Study of saturation magnetization, important in the investigation of the electronic structure of alloys, reveals the effect of aluminum on the saturation moments of iron-nickel alloys. The saturation magnetizations were extrapolated to the absolute zero of temperature for calculating average atomic moments

Aldred, A. T.

Bardos, D. I.

Beck, P. A.

English

NASA Technical Reports Server

May 1968
	 Brief 68-10172 
•::
	
EC-NASA TECH BRIEF 
AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
of the U.S. AEC or from AEC-NASA interagency efforts. They are issued to encourage commercial 
application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Study Reveals Effect of Aluminum on Saturation 
Moment of Fe—Ni Alloys 
The electronic structure of the transition elements 
has been under investigation for over three decades, 
but due to the complexity of the problem, there is still 
no theory that can explain the physical properties 
related to the valence electrons of these elements and 
their alloys. The current study concerns itself with the 
ferromagnetic saturation magnetization of an element 
or an alloy, which is one of its intrinsic properties and 
is entirely dependent on the electronic structure. Thus, 
the measurement of saturation magnetization is an 
important tool in the investigation of the electronic 
structure of alloys. This study, "The Effect of Alumi-
num on the Saturation Moment of Fe-Ni Alloys", 
which is in the form of a doctoral dissertation by D. 1. 
Bardos, is available on request from the Argonne 
National Laboratory. 
It has been known that the addition of a nontransi-
tion metal solute such as aluminum to iron does not 
affect the moment on iron (iron-type behavior), while 
the addition of aluminum to nickel decreases the 
nickel moment by an amount proportional to the 
valence of aluminum (nickel-type behavior). To de-
termine whether these different characteristics of iron 
and nickel are inherent properties of the atomic 
species or simply related to the different structural 
and electronic environments, saturation magnetization 
measurements have been made on the fcc nickel-
rich and bcc iron-rich solid solutions in the iron-
nickel-aluminum system. Several series of alloys were 
made up in which the iron-to-nickel ratio was kept 
constant as the aluminum concentration was in-
creased. 
The principle on which the magnetization meas-
urements were based is that a ferromagnetic specimen
experiences a vertical force when it is in a nonuniform 
magnetic field whose horizontal component changes 
in the z direction. This force is given by the following 
equation
0H 
F = mH,T
	
(dynes) 
liz 
where m is the mass in grams, 0H,T is the intensity of 
magnetization per gram, and liH/3z is the field 
gradient in the vertical direction. The magnetization 
was determined by measuring this force with a semi-
automatic vacuum recording balance in increasing 
fields at various temperatures. 
The saturation magnetizations were extrapolated to 
the absolute zero of temperature for calculating aver-
age atomic moments. 
The results show that in ternary alloys both iron 
and nickel atoms retain their individual characteris-
tics and the magnitude of the magnetic moment on 
each atom depends strongly on the near neighbor 
environment. 
The effect of aluminum on the saturation moment 
of fcc Fe-Ni alloys can be described with the aid of 
the following assumptions: 
(1) There is no atomic magnetic moment associated 
with an aluminum atom. 
(2) The average atomic magnetic moment associ-
ated with the iron atoms is not affected by the 
addition of aluminum to the alloy, but depends 
on the number of Ni nearest neighbors adjacent 
to each Fe atom. 
(3) The decrease in the average atomic moment of a 
nickel atom is the same as that of a binary 
Ni-Al alloy with the same Al content. 
(continued overicaf) 
This document was prepared under the sponsorship of the Atomic 
Energy Commission and/or the National Aeronautics and Space 
Administration. Neither the United States Government nor any per-
son acting on behalf of the United States Government assumes any
liability resulting from the use of the information contained in this 
document, or warrants that the use of any information, apparatus, 
method, or process disclosed in this document may not infringe pri-
vately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19680000172 2020-03-12T05:32:43+00:00Z
Notes: 
1. This information should be of interest to those (I) 
studying the magnetic behavior of metals and 
alloys, and (2) doing solid state research. 
2. Additional details may be found in Journal of 
Applied Physics, vol. 38, no. 3,p. 1260-1262, 
March 1, 1967. 
3. Inquiries concerning this innovation may be di-
.rected to:
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B68-10172 
Source: D. I. Bardos and A. T. Aldred
Metallurgy Division
and P. A. Beck
University of Illinois 
(ARG-90259)
Patent status: 
Inquiries about obtaining rights for commercial use 
of this innovation may be made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439 
Brief 68-10172	 Category 03


Study reveals effect of aluminum on saturation moment of Fe-Ni alloys

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