Magnetic Refrigeration?!?

[singularity]

Hola Comrades!

I'm a newbie here, but I must say the threads in this forum are quite interesting. Might as well stick around for a while.

So I'm working with a group on a project to demonstrate "magnetic refrigeration", having thoroughly understood the concept of the magnetocaloric effect, we are unable to comprehend the construction of the heat exchangers that would provide us with such a high rate of conduction (For rotary type). It seems beyond our current IQ limits. It'd great if you guys could pool in some ideas.

Also, obtaining the element Gadolinium is proving to be a very tedious task, we're in need for some substitutes, Nevermind if they aren't that efficient, we just need to demonstrate the magnetocaloric effect. Any suggestions please?

 

Thank you very much.

[Enthalpy]

¡Hola compañero! Welcome here!

 

http://en.wikipedia.org/wiki/Magnetic_refrigeration#Working_materials

I quote:

"Recent research on materials that exhibit a giant entropy change showed that Gd₅(Si_xGe_1−x)₄, La(Fe_xSi_1−x)₁₃H_x and MnFeP_1−xAs_x alloys, for example, are some of the most promising substitutes for gadolinium and its alloys — GdDy, GdTb, etc. These materials are called giant magnetocaloric effect (GMCE) materials."

and:

"The originally suggested refrigerant was a paramagnetic salt, such as cerium magnesium nitrate."

this one seems to be for low temperature. Same or worse for nuclear demagnetization.

 

Introduction:

http://materialsscience.pwr.wroc.pl/bi/vol26no4/articles/ms_2007_01Szymczak.pdf

 

Last time I vaguely dreamed of magnetic refrigeration, I wanted to have tiny ferromagnetic domains; spaced enough in a matrix so the global material would be just short of ferromagnetic at the working temperature. Anyway, the absorbed heat is small. No idea if it's a sensible way.

Maybe you could experiment with any material just above its Curie temperature? For instance Mn-Zn ferrites are commonly used in electronics. It's just that cooling from hot temperatures needs nothing special...

Edited July 27, 2013 by Enthalpy

[singularity]

That's exactly what my guide professor says. There's another thing, do you suggest we go for reciprocating type of refrigerator or the rotary one? ( In matters of efficiency that is)

Also, do you think using a lame water jacket instead of a complex heat exchanger apparatus would do us any good?

Unlike the one used in this following link -

 

http://origin-ars.els-cdn.com/content/image/1-s2.0-S0140700708000236-gr6.jpg

 

And thanks for the help man!