Thanks for scanning the wire, Geo.? Interesting results, though not surprising.? Although a magnet won’t pick it up, not even a good neodymium magnet, a tiny neodymium magnet will “stick” to it, indicating that it is slightly magnetic.? As you’ve ascertained, it is very hard, to the point it is difficult to cut it with wire cutters.? Well, at least, much more difficult than similar gauge iron or steel wire.

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I pulled out a cheap micrometer (0.05 mm resolution), and the diameter comes out somewhere between 0.95 and 1.00 mm, or roughly 18-gauge.? Assuming a diameter of 0.975 mm, or 0.0975 cm, the cross-sectional area is 7.47E-3 cm^2.? A 10-cm piece of the wire would have a volume of 0.0747 cm^3, and has a mass of 0.65 grams.? That would equate to a density of 8.7 g/cm^3.? For comparison, here’s a table of the densities of the various elements that showed up in Geo’s XRF scan:

Cr:? 7.19 g/cm^3

Fe:? 7.88 g/cm^3

Ni:? 8.90 g/cm^3

Cu:? 8.92 g/cm^3

Mo: 10.22 g/cm^3

Ru: 12.41 g/cm^3

Sn:? 7.29 g/cm^3

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It is moderately resistive as well, though nowhere as resistive as nichrome.? Many years ago I made up a jig consisting of a regulated DC voltage source feeding a chain of a 3-ft chunk of the wire in series with a 1% 100-ohm resistor.? I had a digital multimeter in the chain measuring the total current flowing through the series circuit, and then used another digital multimeter to measure the voltage across each of the individual ‘resistors’ in the circuit.? It was easy enough to use Ohm’s Law to solve for the “unknown” resistance represented by the 3-ft length of “mystery wire”…? R = E ÷ I.? I don’t remember the results now, but perhaps I’ll try to cobble the setup together again and repeat the experiment.? If I get the chance, I’ll report the results here.

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Thanks again, George.

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Hi Geo,

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I moved in June 2019, so there are still boxes of junk (er, I mean “components”) waiting to be unpacked.? I couldn’t find my 1% 100-Ohm power resistor or original test jig, but was able to dig up a 3% 110-Ohm 25-watt resistor and some jumper wires.? I found the longest piece of the mystery wire I could easily lay out on the floor to measure, and it came out to 354 inches, or just shy of 900 cm.? Hooked up in series with the 110-Ohm resistor to a 12-volt regulated power supply, the average current through the circuit was 100.5 mA, producing a voltage of 807.3 mV across the mystery-wire resistor.? Solving by Ohm’s law, the resistance worked out to 807.3 mV ÷ 100.5 mA = 8.033 Ohms.? Dividing by the length of wire (899 cm), that works out to a resistivity of 0.00893 Ohms/cm.? Converting to more conventional units, that’s 893 Ohms/1000 meters, or 272 Ohms/1000 ft.? By comparison, 18-gauge copper wire (closest to 0.975 mm dia), has a resistivity of 20.94 Ohms/1000 meters.? Bottom line, the “mystery wire” has a resistivity that is 43-times greater than that of similar-sized coper wire.? I tried a shorter length of wire, as well as different power supply voltages, and all of the resistivity measurements came out very close to 0.0089 Ohms/cm.

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For what it’s worth, the power dissipation through the 110-Ohm resistor was about 1.1 Watts, and about 0.08 Watts through the 900-cm length of wire.? With these low power dissipation values, there should have been minimal heating effects that could affect the resistance as the components heated up.

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I hope this helps? --? Ken

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Greetings to the group,

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Some more interesting properties of the “mystery wire”.? Although I don’t have a way to quantify the results, I can at least qualify the results.

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Regarding the magnetic properties of the wire, it appears to be somewhat “neutral”.? I tried to qualify this in two manners.? I hooked up a small solenoid coil to an inductance meter and determined the inductance of the “bare” core,? that is, nothing within the cavity of the core.? The result was 0.42 mH.? As expected, if I introduced a steel screwdriver into the cavity (ferromagnetic composition, that is, can be formed into a ‘permanent’ magnet), the inductance increased (1.53 mH).? If I introduced a few strands of 16-gauge copper wire (diamagnetic composition, that is, repelled by a magnetic field) into the core, the inductance decreased (0.38 mH). ?A roll of aluminum (paramagnetic composition, that is attracted to a magnetic field) also decreased the inductance (0.39 mH).? When I introduced several strands of the mystery wire into the cavity, the inductance didn’t change at all, suggesting that it may be only paramagnetic (attracted to a magnetic field, although in this case only slightly to a strong neodymium magnet).

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Along a similar vein, I pulled out a cheap metal detector and checked its response to various metals.? When the discriminator was properly tuned and producing a steady tone, a pair of pliers or screwdriver (both steel/iron) produced a softer or absent tone, whereas a spool of copper produced a stronger/louder tone. A spool if the “mystery wire” resulted in no change in the tone when the metal detector passed over it.

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Although metal, the “mystery wire” appears to be almost ‘neutral’ in its response to a magnetic fields.? Granted, a small piece (<1 cm) of the wire will “stick” very loosely to a strong neodymium magnet, it does not appear to produce any detectable response to my two electromagnetic tests. I will admit neither test is by no means quantitative, but I do find the qualitative results intriguing.

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When Geo suggested the wire might be some type of “supermetal”, it made me start thinking.? I began to wonder if the composition of the wire was deliberately “tuned” to have a neutral response.? A bit of background into the wire.? I used to work at a facility that had some E-field sensors around it to detect potential intruders.? The “mystery wire” used to be stretched along the perimeter of the facility to detect any objects entering within the vicinity of the wires.? I have no idea if the process worked on detecting changes in inductance, capacitance, or both, but if one were attempting to minimize the inductive response, it might make sense to “tune” the wire composition to be relatively ‘neutral’, that is, neither ferromagnetic (e.g., steel wire), diamagnetic (e.g., copper wire), and minimally paramagnetic.? On top of that, the mixture is strong, stiff, hard, resilient, and has a high tensile strength.? All of these properties would lend well to creating an E-field sensor.

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All speculation on my part.? Thanks for your analyses, George.? Like you said, aren’t supermetals a hoot??

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Ken

Interesting observation, Geo.? I had noticed the same thing, that the end seems to be more ‘magnetic’ than the sides.? It might be interesting to take a weak magnet and try the same thing with a more strongly magnetic object like a paperclip or small screw.? I’m guessing this phenomenon is NOT unique to the “mystery wire”.

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I know if you “pick up” a pile of pins or paperclips with a magnet, they stick together end-to-end, versus side-to-side.? Same goes for picking up a screw with a slightly magnetized screwdriver… the attraction seems stronger at the ends of the screw, rather than along its length.? I wonder if the intensity of the magnetic flux is stronger on the small cross section of the end of a relatively long (much larger in length compared to diameter), than if the field is dispersed along the length of the object when picking it up along its side.

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I’m guessing your observation has more to do with the physics behind magnetic fields, than it has to do with the homogeneity of the elemental composition of the wire itself.? I guess that there might be a possibility the “mystery wire” has an iron/steel core, and is otherwise plated/clad/coated with the other metallic components.? I guess one could stick the wire into the chuck of a drill and grind off the outer layer, and reanalyze it with the XRF.? If there is a coating on the wire, the new XRF should be different than the first.? However, if the wire is homogeneous in composition throughout, then the two spectra should be relatively the same.

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That was actually the impetus behind my first question related to ‘resolution’ (for lack of better terms) of XRF in delineating a homogeneous-composition alloy from a plated/coated object containing the same elemental mix.? The example of brass alloy versus the copper-clad penny.

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Thanks for all of your efforts in this inquiry, Geo.

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I hope everyone has a fantastic weekend --? Ken

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I think you’re right, Dud.? I questioned the identification of Kr and Ru, but didn’t pursue the possibilities of Kb or sum peaks. Both of your arguments seem like probable explanations given the other constituents in the wire. Krypton would be very unlikely, given its atmospheric content of only 0.000114%. Given that most of the elements in the mystery wire are near-ferrous, the Kb energy from Mo makes more sense for the 19.6 keV peak.

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Thanks for your insights? --? Ken

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