BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] This invention relates to amorphous metal alloys and, more particularly, to cobalt
rich amorphous metal alloys that include certain transition metal and metalloid elements.
2. Description of the Prior Art
[0002] There are three physical parameters which can inhibit the easy magnetization and
demagnetization of magnetic materials: strong anisotropy, non-zero magnetostriction
and, at high frequencies, low resistivity. Metallic glasses generally show resistivities
greater than 100 micro ohm cm, whereas crystalline and polycrystalline magnetic metals
generally show resistivities below 50 micro ohm cm. Also, because of their randomly
disordered structures, metallic glasses are typically.isotropic in their physical
properties, including their magnetization. Because of these two characteristics, metallic
glasses have an initial advantage over conventional magnetic metals. However, metallic
glasses do not generally show zero magnetostriction. When zero magnetostriction glasses
can be found they are generally good soft magnetic metals (R.C. O'Handley, B.A. Nesbitt,
and L.I. Mendelsohn, IEEE Trans Mag-12, p. 942, 1976, U.S. Patents Nos. 4,038,073
and 4,150,981), because they satisfy the three approved criteria. For this reason,
interest in zero magnetostriction glasses has been intense as indicated by the many
publications on low magnetostriction metallic glasses (A.W. Simpson and W.G. Clements,
IEEE Trans Mag-11, p. 1338, 1975; N. Tsuya, K.I. Arai, Y. Shiraga and T. Masumoto,
Phys. Lett. A51, p. 121, 1975;
H.A. Brooks, Jour. Appl. Phys. 47,
p. 334, 1975; T. Egami, P.J. Flanders and C.D. Graham, Jr., Appl. Phys. Lett. 26, p.
128, 1975 and AIP Conf. Proc. No. 24, p. 697, 1975; R.C. Sherwood, E.M. Gyorgy, H.S.
Chen, S.D. Ferris, G. Norman and H.J. Leamy, AIP Conf. Proc. No. 24, p. 745, 1975;
H. Fujimori, K.I. Arai, H. Shiraga, M. Yamada, T. Masumoto and N. Tsuya, Japan, Jour.
Appl. Phys. 15, p. 705, 1976; L. Kraus and J. Schneider, phys. stat. sol. a39, p.
K161, 1977; R.C. O'Handley in Amorphous Magnetism, edited by R. Levy and R. Hasegawa
(Plenum Press, New York 1977), p. 379; R.C. O'Handley, Solid State Communications
21, p. 1119, 1977; R.C. O'Handley, Solid State Communications 22, p. 458, 1977; R.C.
O'Handley, Phys. Rev. 18, p. 930, 1978; H.S. Chen, E.M. Gyorgy, H.J. Leamy and R.C.
Sherwood, U.S. Patent No. 4,056,411, Nov. 1, 1977).
[0003] The existence of a zero in the magnetostriction of Co-Mn-B glasses has been observed
by H. Hilt- zinger of Vacuumschmeltze A.G., Hanau, Germany.
[0004] Reference to Co-rich glasses containing 6 atom percent of Cr is made by N. Heiman,
R.D. Hempstead and N. Kazama in Journal of Applied Physics, Vol. 49, p. 5663, 1978.
Their interest was in improving the corrosion resistance of Co-B thin films. No reference
to magnetostriction is made in that article.
[0005] Saturation moments and Curie temperatures of Co
80-xT
xP
10B
10 glasses (T = Mn, Cr, or V) were recently reported by T-. Mizoguchi in the Supplement
to the Scientific Reports of RITU (Research Institutes of Tonoku University), A June
1978, p. 117. No reference to their magnetostrictive properties was reported.
[0006] In Journal of Applied Physics, Vol. 50, p. 7597, 1979, S. Ohnuma and T. Masumoto
outline their studies of magnetization and magnetostriction in Co-Fe-B-Si glasses
with light transition metal (Mn,
Cr, V, W, Ta, Mo and Nb) substitutions. They show that the coercivity decreases and
the effective permeability increases in the composition range near zero magnetostriction.
[0007] New applications requiring improved soft zero- magnetic materials that are easily
fabricated and have excellent stability have necessitated efforts to develop further
specific compositions.
SUMMARY OF THE INVEnTIOn
[0008] The present invention provides low magnetostriction and zero magnetostriction glassy
alloys that are easy to fabricate and thermally stable. The alloys are at least about
50 percent glassy and consist essentially of compositions defined by the formula:
(Co
1-xT
x)
100-b(B
1-yY
y)b' where T is at least one of Cr and V, Y is at least one of carbon and silicon,
B is boron, x ranges from about .05 to .25, y ranges from about 0 to .75, and b ranges
from about 14 to 28 atom percent. The alloys of the invention have a value of magnetostriction
ranging from about -6 x 10
-6 to 4 x 10-
6 and a saturation induction of about 0.2 to 1.OT.
[0009] In addition, the invention provides cobalt- iron-nickel base and nickel-rich magnetic
alloys that are easily fabricated and thermally stable. The cobalt- iron-nickel base
alloys are at least 50 percent glassy and consist essentially of compositions defined
by the formula: (Co
1-x-y-zFe
xNi
yT
z)
100-b(B
1-wM
w)
b, where T is at least one of Mn, Cr, V, Ti, Mo, Nb and W, M is at least one of Si,
P, C and Ge, B is boron, x ranges from about .05 to .25, y ranges from about .05 to
.80, z ranges from about 0 to .25, b ranges from about 12 to 30 atom percent, w ranges
up to .75 when M is Si or Ge and up to .5 when M is C or P. These alloys have a value
of magnetostriction of about -7 x 10 and +5 x 10 and a saturation induction of about
0.2 to 1.4T. The nickel-rich alloys are at least 50 percent glassy and consist essentially
of compositions defined by the formula: (Ni
.5Co
.5-xT
x)
100-bB
b, where
T is at least one of Mn,
Cr and V, B is at least one of B, Si, P, C and Ge, x is less than 0.25, and b ranges
from 17 to 22 atom percent. The nickel-rich alloys have a value of magnetostriction
of about -8 x 10
-6 to +2 x 10
-6 and a saturation induction of about 0.3 to 0.8 T.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will be more fully understood and further advantages will become apparent
when reference is made to the following detailed description of the preferred embodiments
of the invention and the accompanying drawings, in which
Figure 1 is a graph showing saturation magnetization for compositions defined by the
formula Co80-xTxB20, where T is at least one of Fe, Mn, Cr and V and x ranges up to about 16 atom percent;
Figure 2 is a graph showing Curie temperatures of compositions for which Tc is below the crystallization temperature Tx;
Figure 3 is a graph showing the relationships between saturation magnetostriction
and composition for selected alloys of the invention;
Figure 4 is a graph showing the relationships between temperature and magnetostriction
values for selected alloys of the invention;
Figure 5 shows the cobalt-rich corners of triangular diagrams for compositions defined
by the formula (Co1-x-yFexTy)80B20, where T is at least one of V, Cr, Mn, Fe, Co and Ni; and
Figure 6 is a triangular Fe-Co-Ni diagram showing regions of positive and negative
magnetostriction, the dotted line isolating therefrom the region of nickel-rich compositions
wherein amorphous metals are difficult to form and thermally unstable.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] In accordance with the invention, there is provided a magnetic alloy that is at least
50 percent glassy and consists essentially of the composition: (Co
1-xT
x)
100-b(B
1-yY
y)
b, where T is at least one of chromium and vanadium, Y is at least one of carbon and
silicon, x ranges from about .05 to .25, y ranges from about 0 to .75, and b ranges
from about 14 to 28 atom percent. The glassy alloy has a value of magnetostriction
of about -6 x 10
-6 to 4 x 10
-6 and a saturation induction of about 0.2 to 1.0T.
[0012] The purity of the above composition is that found in normal commercial practice.
However, it will be appreciated that the alloys of the invention may contain, based
on total composition, up to about 5 atom percent of at least one other transition
metal element, such as Fe, Co, Ni, Cu, Zn, Mn, Cr, V, Ti, Zr, Nb, Ta, Mo, W, Ru, Rh
and Pd, and up to about 2 atom percent based on total composition of at least one
other metalloid element, such as B, C, Si, P, Ge, Al, N, 0 and S, without significantly
degrading the desirable magnetic properties of these glassy alloys.
[0013] The amorphous alloys of the invention can be formed by cooling a melt of the composition
at a rate of at least about 10 °C/sec. A variety of techniques are available, as is
now well-known in the art, for fabricating splat-quenched foils and rapid-quenched
continuous ribbons, wire, sheet, etc. Typically, a particular composition is selected,
powders of the requisite elements (or of materials that decompose to form the elements,
such as nickel-borides, etc.) in the desired proportions are melted and homogenized,
and the molten alloy is rapidly quenched either on a chill surface, such as a rotating
cooled cylinder, or in a suitable fluid medium, such as a chilled brine solution.
The amorphous alloys may be formed in air. However, superior mechanical properties
are achieved by forming these amorphous alloys in a partial vacuum with absolute pressure
less than about 5.5 cm of Hg, and preferably about 100 µm to 1 cm of Hg, as disclosed
in U.S. Patent No. 4,154,283 to Ray et al.
[0014] The amorphous metal alloys are at least 50 percent amorphous, and preferably at least
80 percent amorphous, as measured by X-ray diffraction. However, a substantial degree
of amorphousness approaching 100 percent amorphous is obtained by forming these amorphous
metal alloys in a partial vacuum. Ductility is thereby improved, and such alloys possessing
a substantial degree of amorphousness are accordingly preferred.
[0015] Ribbons of these alloys find use in soft magnetic applications and in applications
requiring low magnetostriction, high thermal stability (e.g., stable up to about 100°C)
and excellent fabricability.
[0016] The following example is presented to provide a more complete understanding of the
invention. The specific techniques, conditions, materials, proportions and reported
data set forth to illustrate the principles and practice of the invention are exemplary
and should not be construed as limiting the scope of the invention.
EXAMPLE
[0017] An alloy melt of known composition was rapidly quenched to form non-crystalline ribbons,
presumably of the same composition as the melt. The ribbons, typically 40 micrometers
(um) by 2 mm in cross section, were cut into squares for vibration-sample magnetometer
measurements of specific magnetization σ(4.2K, 9 KOe) and σ(T, 9 KOe) with 295 K <
T < T
x, the crystallization temperature. Curie temperatures were obtained from the inflection
points in the σ(T, 9 KOe) curves.
[0018] The magnetostriction measurements were made in fields up to 4 KOe with metal foil
strain gauges (as reported in more detail by R.C. O'Handley in Solid State Communications,
Vol. 22, p. 485, 1977). The accuracy of these measurements is considered to be within
10 percent of full strain and their strain sensitivity is on the order of 10
-7.
[0019] Composition variations of the room temperature specific saturation magentizations
a(295 K, 9 KOe) as functions of composition x for Co
80-xT
xB
20 (T
= Fe, Mn, Cr, V) glasses are shown in Figure 1. The trends in Figure 1 reflect the variations
of both the saturation moments n
B and the Curie temperatures T
C of these alloys.
[0020] The Curie temperatures of Co-rich glasses are generally well above the temperatures
for crystallization T
x but fall below T
x for sufficiently large additions of Cr or V (Figure 2).
[0021] In order to be useful in magnetic devices, materials should show appreciable magnetization.
Commercial zero magnetostriction crystalline metallic alloys of the class exemplified
by Permalloy ((Ni
82Fe
18)
1-xX
x with
x = MO or Cu and x < .04) have saturation inductions B = H + 4 π M
s = 4 π M
s of about 0.6 to 0.8 tesla (6 to 8 kGauss). The specific magnetizations in Figure
1 can be converted to tesla by multiplying by the mass density times 4 π/10,000. Densities
for the glasses studied here can be estimated from the measured densities for Co
80B
20, Fe
80B
20 and Co
70Fe
10B
20 glasses and the known densities of crystalline Co, Fe, Mn, Cr and V.
[0022] Defining p
x to be the mass density of the crystalline material X and ρ
g to be that of the glassy material X80B20, the ratios of the measured quantities ρ
g/ρ
x were found to be 0.92 and 0.94 for Co
80B
20 and Fe
80 B
20 glasses. A similar trend holds for the hypothetical
X80B20 glasses listed in Table I. The estimated densities of X
80B
20 (X = Mn, Cr, V) glasses are also set forth in Table I. The densities of CO
70X
10B
20 glasses were calculated by linearly combining the densities of Co
80B
20 and X
80B
20. The value so obtained for Co
70Fe
10B
20 is less than 1 percent larger than the measured density for that glass.
[0023] In Figure 3, there is shown the effects of Fe, Mn, Cr and V substitutions on the
saturation magnetostriction of Co
80B
20 glass. As is the case with the Fe substitutions for Co disclosed by U.S. Patent No.
4,038,073 to O'Handley et al., the lighter transition metals cause λ
s to increase through zero, positive below T for Mn and Cr substitutions and go to
zero for V sub- stitutions. In the case of Co
66V
14B
20 glass,
Tc = 300 K (Fig. 2). Thus, the room temperature magnetostriction is zero probably because
of the low T . Co
80-xV
xB
20 glasses with x > 14 may show positive
mag-netostriction at 4.2 K (see Fig. 4). These Co-Mn-B and Co-Cr-B glasses are, therefore,
non-magnetostrictive alloys. Co
74Fe
6B
20 and related glasses are non-magnetostrictive alloys that have approximately two times
the magnetization of the permalloys for which λ= 0. Co
71Mn
9B
20 glass is in the same category, with X= 0 and 0(295 K = 111 emu/gm (4πM = 11 kGauss).
[0024] The temperature dependence of λ
S is shown in Figure 4 for selected alloys. The sign of λ
S was observed to change in two of the glasses. Such compensation temperatures have
not previously been observed in metallic glasses. The vanadium containing glasses
either become paramagnetic or they crystallize before any compensation can be realized.
Thus, the negative magnetostriction glasses shown in Figure 3 may be used in applications
requiring λ
S = 0 at some elevated temperature (up to approximately 200°C above room temperature,
which is not uncommon in many electronic devices).
[0025] The new low magnetostriction metallic glasses disclosed herein (Co-Cr-B and Co-V-B)
show relatively low 4πM
S (Fig. 1). As a result, their utility is limited to applications requiring superior
mechanical properties or improved corrosion resistance relative to permalloys or other
λ
S = 0 crystalline or non-crystalline materials.
[0026] Co-rich glass compositions with positive and negative magnetostriction can be added
linearly to give zero magnetostriction. For example, λ
S for Co
70Fe
10B
20 and Co
80B
20 glasses are +4 and -4 x 10 6, respectively. A 50-50 percent mixture of these glasses
gives Co
75Fe
5P
20 which does in fact show λ
S = 0 (O'Handley et al., IEEE Trans Mag-12, p. 942, 1976). Similarly, for Co
40Ni
40B
40 x
s = -7 x 10
-6 while for Fe
80B
20 λ
S = 32 x 10
-6. A linear mixture having λ = 0 would be 0.18 x (Fe
80B
20)
+ 0.8
2 x (Co
40Ni
40B
20) = Co
33Ni
33Fe
14B
20 which is very close to the observed λ
S = 0 comoosition,
Co 33.5 Ni
33.5 Fe 13 B 20 .
[0027] The rule bf linear combination of opposing magnetostrictions (LCOM) has been applied
to develop additional zero magnetostriction glasses from those measured and shown
in Figure 3. Table II lists several such glasses and Figure 5 shows where they fall
in the Co-rich corner of a triangular composition diagram. The lines connecting these
newly developed λ
S = 0 compositions closely follow the observations of Ohnuma and Masumoto (cited above)
for (Co Fe X)
78B
14Si
8 glasses (with X = Mn, Cr, V) despite the different metalloids used in the two cases.
[0028] The magnetostriction of Co-rich glasses is small because of the near-cancellation
of two independent mechanisms for the magnetostriction, a positive two-ion interaction
and a negative single-TM-ion term (O'Handley, Phys. Rev. B 18, p. 930, 1978). As a
result, the TM makeup for λ
S = 0 is nearly independent of TM/M ratio. That is, because λ
S = 0 for (Co
.94Fe
.06)
80B
20, is nearly zero for other compositions (Co
.94Fe
.06)
100-xB
x such that 12 < x < 28 atom percent. An improvement on this approximation can be realized
by taking into account the fact that the strength of the negative single-ion term
varies linearly with the concentration of magnetic ions, i.e., at (100-x). The two-ion
term should vary as the number of TM pairs at short range. However, observed trends
in Co
100-xB
x glasses (K. Narita, J. Yamasaki, and H. Fukunaga, Jour. Appl. Phys. Vol. 50, p. 7591,
1979 and J. Aboaf and E. Klokholm, ICM Munich Sept. 1979 to appear in Jour. Magnetism
and Magnetic Materials), are best described by assuming the number of nearest neighbor
TM pairs to be independent of x. This implies that the nearest- neighbor coordination
of cobalt atoms by cobalt atoms does not vary strongly with x. Thus the compositional
dependence of magnetostriction in Co-rich glasses is well described at room temperature
by: λ
S α+ 6.8 x 10 6 - 10.2 x 10
-6 x (100-x)/80 where the first term is the observed two-ion component of magnetostriction
(independent of composition x) and the second is the single-ion component of magnetostriction
(which varies linearly with the TM concentration). Thus the magnetostriction becomes
less negative as metalloid content increases, the change in λ being +0.13 x 10
-6 per atom percent more metalloid. Alternatively, the zero magnetostriction composition
is shifted to glasses richer in iron as 100-x increases, the shift being approximately
+0.23 percent Fe per
1 percent decrease in x.
[0029] As a result, the Co-Fe-T ratios (T = Mn, Cr, V) for λ
S = 0 in Figure 5 hold approximately for other TM/M ratios in the glass-forming range
12 < x < 28 atom percent. A first order correction shifts the λ
S = 0 lines toward Fe by approximately 1 percent for every
4 percent decrease in x.
[0030] Metalloid type has little effect on the magnitude or sign of magnetostriction in
Co-rich glasses (O'Handley in Amorphous Magnetism eds. R. Levy and R. Hasegawa, Plenum
Press 1977, p. 379). Hence, the compositions in Table II and Figure 5 will still be
of near-zero magnetostriction if B is replaced by P, C, Si or some combination of
these metaloids.
[0031] The rule of linear combination of opposing magnetostrictions (LCOM) can also be applied
across the Co-Ni side of the Fe-Co-Ni triangular magnetostriction diagram shown in
Figure 6 (see also U.S. Patent No. 4,150,981 to O'Handley). Table III sets forth some
typical near-zero magnetostriction compositions.
[0032] Referring to Figure 6, a region of difficult to fabricate and relatively unstable
glasses exists in the Ni-rich corner of the triangular Fe-Co-Ni diagram. Yet, glassy
alloys of zero or low magnetostriction exist there with potential for various applications.
[0033] Ni-rich glasses are more easily made and are more stable if the "late" transition
metal Ni is balanced to a certain extent by an "early" TM, e.g., Mn, Cr, V. Examples
of such glasses include Ni
50Mn
30B
20, Ni
60Cr
20B
20, or Ni
70V
10B
20.
[0034] Based on the evidence of λ
S = 0 alloys set forth above and the known stabilizing effects of light TM's on Ni-rich
glasses, new low magnetostriction glasses rich in Ni have been developed in the region
below or near the λ = 0 line in Figure 8 (i.e., glasses s initially showing λ
S < 0) by the addition of Mn, Cr, and/or V. Thus, for example, (Co
.25Ni
.75)
80B
20 can be rendered more fabricable and more stable in the glassy state, and its negative
magnetostriction can be increased to near zero by substituting Mn, Cr or V for Co:
(Ni
.75Co
.25-xT
x)
80B
20.
[0035] Having thus described the invention in rather full detail, it will be understood
that such detail need not be strictly adhered to but that various changes and modifications
may suggest themselves to one skilled in the art, all falling within the scope of
the invention as defined by the subjoined claims.
1. A magnetic alloy that is at least auout 50 percent glassy, having the formula (Co1-xTx)100-b(B1-yYy)b, where T is at least one of chromium and vanadium, Y is carbon, silicon, Phosphorus
and germanium, x ranges from about .05 to .25, y ranges from about 0 to .75, and b
ranges from about 14 to 28 atom percent, said alloy containing, as transition metal
impurities, up to 5 atom percent of the total alloy of at least one of Fe, Co, Ni,
Cu, Zn, Mn, Cr, V, Ti, Zr, Nb, Ta, Mo, W, Ru, Rh and Pd, ana, as metalloid impurities,
up to 2 atom percent of the total alloy of at least one of B, C, Si, P, Ge, Al, N,
O and S, having a value of magnetostriction of about -6 x 10-6 to 4 x 10-6 and a saturation induction of about 0.2 to 1.0T.
2. A magnetic alloy, as recited in claim 1, wherein x ranges from about .05 to .15,
y ranges from about 0 to .25 and b ranges from about 17 to 22 atom percent said alloy
having a value of magnetostriction of about -3 x 10-6 to +1 x 10-6 and a saturation induction of about 0.3 to 0.6T.
3. A magnetic alloy that is at least 50 percent glassy, naving the formula (Co1-xTx)100-bBb, where T is at least one of chromium and vanadium, b ranges from about 18 to 22 atom
percent and x ranges from 2 to 16 atom percent, said alloy further containing, as
transition metal impurities, up to 5 atom percent of the total alloy of at least one
of Fe, Co, Ni, Cu, Zn, Mn, Cr, V, Ti, Zr, Nd, Ta, Mo, W, Ru, Rn and Pd, and, as metalloid
impurities, up tc 2 atom percent of the total alloy of at least one of B, C, Si, P,
Ge, Al, N, O and S.
4. A magnetic alloy that is at least 50 percent glassy, naving the formula (Co1-x-y-zFexNi Tz)100-b (B1-wMw)b, wnere T is at least one of Mn, Cr, V, Ti, Mo, Nb and W, M is at least one of Si,
P, C and Ge, b is boron, x ranges from about .05 to .25, y ranges from about .05 to
.80, z ranges from about 0 to .25, b ranges from about 12 to 30 atom percent, w ranges
up to .75 when M is Si or Ge and up to .5 when M is C or P, said alloy having a value
of magnetostriction of about -7 x 10-6 and +5 x 10-6 and a saturation induction of about 0.2 to 1.4T.
5. A magnetic alloy, as recited in claim 4, wherein y ranges from about 0.3 to 0.6
or between 0.60 to 0.80 and z is respectively less than 0.2 or less than 0.15 when
T is more than 50 percent of at least one uf Cr and V, said alloy having a value of
magnetostriction of about -6 x 10-6 to +4 x 10-6 and a saturation induction of about 0.1 to 0.9T.
6. A magnetic alloy that is at least 50 percent glassy, having the formula (Ni.5Co.5-xTx)100-bBb, where T is at least one of Mn, Cr and V, B is at least one of B, Si, P, C and Ge,
x is less than 0.25, and b ranges from 17 to 22 atom percent, said alloy naving a
value of magnetostriction of aoout -8 x 10-6 to +2 x 10-6 and a saturation induction of about 0.3 to 0.8T.
7. A magnetic alloy that is at least 50 percent glassy, said alloy having the formula
(Ni.75Co25-xTx)100-bMb, where T is at least one of Mn, Cr and V, M is at least one of B, Si, P, C and Ge
x ranges up to about 0.25, and b ranges from, about 17 tu 22 atom percent, said alloy
having a value of magnetostriction of about -6 x 10-6 to +2 x 10-6 anu a' saturation induction of about 0.1 to 0.7T.
8. A magnetic alloy, as recited in either claim 6 or 7, wherein M is essentially boron
and said alloy contains, as metalloid impurities, up to 2 atom percent of at least
one of B, Si, P, C and Ge.
9. A magnetic alloy having a composition selected from the group consisting of Co73Fe4.5Mn2.5B20, Co73Fe2.5Mn4.5B20, Co73Fe5Cr2B20, Co70Fe2.5Cr7.5B20, Co73Fe3.5V3.5B20, Co70.5Fe2.5V7B20, Co70Mn5V5B20, Co66Cr8V6B20, Co73Fe2Mn5B20, Co71Fe4.5Cr4.5B20, Co71Fe3V6B20, Co72.3Fe4.3V3.4B20 and Co69Mn5Cr6B20.
10. A magnetic alloy having a composition selected from the group consisting of Co66Mn 9Ni5B20 Co53.7Ni15.3Fe5.5Mn5.5B20 Co41Ni30Fe5Mn4B20, Co58Ni12Fe6Mn4B20, Co58Ni12Fe6Mn4B20, Co51Ni18Fe8Cr3B20, Co56Ni12Fe6Cr6B20, Co40Ni30Fe5B20, Co68.4Mn8.3Ni3.3B20, Co52Ni18Fe8Mn2B20, Ni45Co26.5Fe7.5Mn1B20, Co39Ni30Cr6Fe5B20, Co51Ni18Fe9Cr2B20 and Co59Ni12Fe6V5B20.
11. A magnetic alloy tnat is at least 50 percent glassy, said alioy naving tne formula
Co 80-xT xB20, wnere T is at least one of Cr and V, B is boron, and x ranges from about 0 to 16
atom percent.