Cobalt-niobium amorphous ferromagnetic alloys

Claim 2

An amorphous ferromagnetic alloy containing 2.5 to 15% niobium and less than 12% boron and made by rapid solidification.

Claim 3

A marker for use in an electronic article surveillance system, the marker comprising: a marker element for producing a detectable response and including an amorphous ferromagnetic element made from a molten alloy containing 2.5 to 15% niobium, and a carrier for the marker element.

Claim 4

A marker for use in an electronic article surveillance system, the marker comprising: a marker element for producing a detectable response and including an amorphous ferromagnetic element made from a molten alloy containing 2.5 to 15% niobium, and a carrier for the marker element.

Claim 5

The marker of claim 2 wherein said amorphous ferromagnetic marker is a fiber.

Claim 6

The marker of claim 2 wherein said amorphous ferromagnetic marker is a ribbon.

Claim 7

The marker as defined in claim 2 wherein said ferromagnetic fiber is produced from said molten alloy by rapid solidification techniques.

Claim 8

A marker for use in an electronic article surveillance system, the marker comprising: an amorphous ferromagnetic element having 2.5 to 15% niobium, a length less than 15 millimeters and cross-sectional area of less than 6×10 -3 square millimeters.

Claim 9

A marker for use in an electronic article surveillance system, the marker comprising: an amorphous ferromagnetic element having 2.5 to 15% niobium, a length less than 15 millimeters and cross-sectional area of less than 6×10 -3 square millimeters.

Claim 10

The marker of claim 6 wherein said amorphous ferromagnetic element is a fiber.

Claim 11

The marker of claim 6 wherein said amorphous ferromagnetic element is a ribbon.

Claim 12

A marker as defined in claim 6, wherein the marker element has a t1/2 value of less than 10 microseconds at 6 kHz.

Claim 13

A web of markers for use in an electronic article surveillance system, the web comprising: a web of labels and a plurality of amorphous, ferromagnetic marker elements having a composition containing 2.5 to 15% niobium and supported by each of the labels for producing a detectable response.

Claim 14

A web of markers for use in an electronic article surveillance system, the web comprising: a web of labels and a plurality of amorphous, ferromagnetic marker elements having a composition containing 2.5 to 15% niobium and supported by each of the labels for producing a detectable response.

Claim 17

The method as defined in claim 11, wherein the incorporating step includes incorporating the element into fabric.

Claim 18

The method as defined in claim 11, wherein the incorporating step includes adding the element into a paper-making slurry, and converting the slurry into paper.

Claim 19

The method as defined in claim 11, further comprising the step of cutting the element into a plurality of pieces, and wherein the incorporating step includes mounting the pieces on a plurality of support members.

Claim 20

The method as defined in claim 14, wherein the cutting step includes cutting the element into a plurality of fiber pieces each having a predetermined length.

Claim 23

A marker for producing a detectable response in an electronic article surveillance system, the marker comprising: a support element, an amorphous, ferromagnetic fiber having a composition containing 2.5 to 15% niobium supported by the support element, the fiber having a cross sectional area of less than 6×10 -3 square millimeters.

Claim 24

A marker for producing a detectable response in an electronic article surveillance system, the marker comprising: a support element, an amorphous, ferromagnetic fiber having a composition containing 2.5 to 15% niobium supported by the support element, the fiber having a cross sectional area of less than 6×10 -3 square millimeters.

Claim 25

A ferromagnetic marker for use in an article surveillance system comprising: an amorphous ferromagnetic fiber having a composition containing 2.5 to 7.5% niobium and an aspect ratio of greater than 150, said amorphous ferromagnetic fiber being positioned between two dielectric sheets, and said sheets begin joined so as to hold said amorphous ferromagnetic fibers therebetween to form a marker.

Claim 26

A ferromagnetic marker for use in an article surveillance system comprising: an amorphous ferromagnetic fiber having a composition containing 2.5 to 7.5% niobium and an aspect ratio of greater than 150, said amorphous ferromagnetic fiber being positioned between two dielectric sheets, and said sheets begin joined so as to hold said amorphous ferromagnetic fibers therebetween to form a marker.

Claim 27

The ferromagnetic marker of claim 18 wherein said marker has a length of less than one inch.

Claim 28

An amorphous ferromagnetic fiber having a composition containing 2.5 to 15% niobium, a nominal diameter of less than 80 microns and a t1/2 of less than 10 microseconds in a driving frequency of 6 kH z and an amplitude in the order of one Oersted.

Claim 29

An amorphous ferromagnetic fiber having a composition containing 2.5 to 15% niobium, a nominal diameter of less than 80 microns and a t1/2 of less than 10 microseconds in a driving frequency of 6 kH z and an amplitude in the order of one Oersted.

Claim 30

The fiber of claim 20 wherein said fiber has an aspect ratio greater than 150.

Claim 31

The fiber of claim 21 wherein said fiber has a kidney shaped cross section.

Claim 32

The fiber of claim 21 wherein said fiber has a generally circular cross section.

Claim 33

An amorphous ferromagnetic alloy having a composition comprising: Co.sub.a Fe.sub.b Nb.sub.c Si.sub.d B.sub.e "a" ranges from 65 to 79% "b" ranges from 2 to 7% "c" ranges from 2.5 to 15% "d" is less than 16% inclusive "e" is less than 12% inclusive and wherein said ranges are in atomic percent.

Claim 34

An amorphous ferromagnetic alloy having a composition comprising: Co.sub.a Fe.sub.b Nb.sub.c Si.sub.d B.sub.e "a" ranges from 65 to 79% "b" ranges from 2 to 7% "c" ranges from 2.5 to 15% "d" is less than 16% inclusive "e" is less than 12% inclusive and wherein said ranges are in atomic percent.

Claim 35

The amorphous ferromagnetic alloy of claim 24 and ______________________________________ 0 ≦ d + e ≦ 14 when 0 ≦ d ≦ 4 0 ≦ e ≦ 10 when 4 ≦ d ≦ 5 0 ≦ e ≦ 10 when 5 ≦ d ≦ 7 e ≦ 12 and d + e ≧ 17 when 5 ≦ d ≦ 7 0 ≦ e ≦ 12 when 7 ≦ d ≦ 8 0 ≦ d + e ≦ 20 when 8 ≦ d ≦ 12 0 ≦ e ≦ 8 when 12 ≦ d ≦ 15 0 ≦ d + e ≦ 23 when 15 ≦ d ≦ 18 0 ≦ e ≦ 5 when 18 ≦ d ≦ 20 ______________________________________