Hi.

When a magnetocaloric compound is exposed to a magnetic field it heats up; Until when? For how long ? As long as the field increases?

If the material heats up -say 10ºC- ; starts cooling back by radiation/convection/other or maintains:eek: a delta t ?

 

Miguel

As a complete guess I'd say the heat generation withing the material is proportional to the rate of change of magnetic flux.

it draws energy from the magnetic properties of the material to create the heat. so if you keep upping the field strength, the material will keep producing heat up to a point. iirc, it changes the specific heat of the material.

if you release the field, the energy returns to the material with a cooling effect.

you can extract a few joules per unit mass of compund per tesla.

there are a few refrigeration systems that use chains of the stuff going past a magnet.

it draws energy from the magnetic properties of the material to create the heat. so if you keep upping the field strength, the material will keep producing heat up to a point. iirc, it changes the specific heat of the material.

if you release the field, the energy returns to the material with a cooling effect.

you can extract a few joules per unit mass of compund per tesla.

there are a few refrigeration systems that use chains of the stuff going past a magnet.

 

I Think I'm out of my league with you..on an itellectual level of course..but maybe i can teach you about being here in this space and this time?..JRingo

i'm not much involved with magnetocaloric effects nor existential crises...

it would pay you to leave a thread finalised or on topic.

OPs generally don't appreciate hijacked threads.

This sounds like an effective way to produce a verry, verry fast change in tempreture?

 

Im fealing lost trying to find out infomation on the rest of the intenet, anyone know what the most effective material is and what the tempature change for it is?

Hi alan2. Enjoy:

 

http://www.sciencenews.org/articles/20020105/fob2.asp

 

Is not a new article, but lately there is very little noise about the technology.

Miguel

 

Edit-added:

http://www.scirus.com/srsapp/search?q=magnetocaloric+metals&ds=jnl&ds=nom&ds=web&g=s&t=all

TY for the links :¬)

 

Gd5(Si2Ge2) apears to be the most effective materal. Still don't have a rough idea of what scale the effect is on though in this materal.