MnCu Manganese Copper Ferrite?

[aesoton]

Does anybody know a manufcturer of Manganese Copper Ferrites? I am looking for a ferrite that has a low curie temperature and have found a paper that shows various MnCu ferrites with curie temps between 50-100 degC. They seem to have been used i nthe 1960s and 70s but were surpassed by other materials. Does anyone still have the ability to produce them?
Many thanks

 

[FiatfLux]

"Why?" seems to be a very reasonable question.

are you hoping to exploit the curie temp, specifically? I'm certain they can still be produced, and may still be produced, I can find out more in a day or so.

What are you trying to accomplish with these magnets?
I ask because other magnets might be able to do it. or a thermostat?

 

[aesoton]

Hi FiatfLux,
MnCu ferrites are a bit of an off the wall suggestion for my research and I have many other materials that I will be looking at, it's just that these seemed quite promising and didn't want to leave them out of the study.
There are plenty of companies manufacturing other ferrites but some are really just distributors and I only need a small quantity.
If you do know of anywhere that would be able to make some I would be very grateful.

 

[FiatfLux]

A branch of the company I work for does manufacture ferrites, and they may be able to batch a small amount of the composition you're interested in.

That said, any magnetics you could get out of what you've determined to be obsolete magnets can be provided, and with better uniformity, by newer compositions.

What specifically about MnCu ferrites is of interest?

 

[aesoton]

The property I am specifically looking for is the curie temperature, I have a technical paper that states that the curie temp of MnCu ferrites can be made to be around 50 degreesC. Most other ferrites are above 100degC (at least those I have come across.

 

[FiatfLux]

yes, they are pushed higher for motor applications. You want something to become demagnetized at 50°C[~122°F], to achieve...?

What are you hoping to study?

I should hear back whether the aforementioned branch has ever dealt in mncu ferrites. Failing that, I know of two alternatives that may be worth investigating.

 

[aesoton]

Effectively, yes, I want something demagnetised at above say 50 deg to study the effect on some sensors that are sensitive to magnetic fields and whether this will remove a degree of 'noise' from our system or lead us to redesign the packaging. But below 50 I want it magnetised for their usual purpose (different devices in the same box effectively but won't run together). so it's either redesign or seek alternative materials (preferable as everything else is fine).

 

[FiatfLux]

It turns out we can't do a thing with regard to MnCu. You might reach out to Ilpea and Hoosier, both ferrite manufacturers.

As for fitting a magnet into your system, could a small electromagnet work into the design?

Also, to clarify, I presume you realize that hitting the curie temp is a one-way trip? As in, the mncu ferrite would remain demagnetized upon cooling down, thus rendering the low temperature operation of half your sensor suite useless after seeing temps above 50°C

 

[aesoton]

Thanks for the advice and help. I will try the manufacturers that you suggested.