You can probably answer this yourself if you read the articles below, which I found on the first page of my web search.  Try this yourself.

http://www.npl.co.uk/upload/pdf/090617_multiferroics_mcmorrow.pdf

https://nanohub.org/resources/18358/download/NikonovBeyondCMOS_10_magnetoelectric.pdf

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1021&context=physicsfacpub

Thanks! I modified the question, wrote it incorrectly yesterday but the whole question followed up on what I actually wanted to ask. My question was about ME field cooling and what the technique is. Those links only give information about how the basic switching works.

Also, the answer to that is there are different techniques to observe ME spin vector switching(forming domains in the ME materials):

ME field cooling- we heat up the sample to above need temperature and then apply cooling fields.

Isothermal switching- Electric and magnetic fields are applied at a constant temperature to switch the ME material.

A professor I work with helped me out with this! :)

https://www.researchgate.net/publication/308763270_A_novel_perovskite_oxide_chemically_designed_to_show_multiferroic_phase_boundary_with_room-temperature_magnetoelectricity/figures?lo=1

Article A novel perovskite oxide chemically designed to show multife...

    Dear Nishtha,

    I think that your question is without a logic answer because you are not employing right concepts. Let me try to answer you by parts:

   1. Cooling fields don't exist because electromagnetic fields are independent of the thermodynamic magnitudes.

   2. It is true that you can apply an magnetic field on a system an to cool it with effects as Peltier or magnetocaloric, but this is only because you are able to change the entropy of the system by their spin configurations or so on.

   3. Magnetoelectric materials are the ones which can have simultaneously a magnetization M and an electric polarization P (for instance the multiferroics) . Thus they contain electric and magnetic dipoles that can be polarized by one external electric, magnetic or electromagnetic field. If you are able to change their entropy in one significative form then you can change the temperature of this material. This is perhaps the issue that you asking for.

   4. In any case, the electric, magnetic or electromagnetic fields by themselve cannot cool any body or system without using a material able to change its entropy from one given state to other.

   5. Electric, magnetic and electromagnetic fields are always the same concept although it can be applied in many different situations even for refrigeration, but on an external system able to change thermodynamically.

   I hope this helps.

Dear Daniel,

Thanks! I have attached the paper I was referring to. 

Hi Nistha,

This is Chun! :-) I am preparing for my topic defense at the moment and came across your question. Since you know what it is now, I will try to address why we do it, or what does it do to the system.

I don't have a quantitative answer to this. But I refer you to the paper 'Magneto- electric annealing effects of Cr2O3' by T. J. Martin and J. C Anderson on Physics Letters, number 11, volume 2 (1964). And the following is an excerpt:

'However, the presence of an electric field above Neel point will still result in the spins on one sublattice being increased, those on the other being decrease. Cooling in the simultaneous presence of a B field causes the sublattice with larger spin to line up with applied B field, the smaller being forced to become anti- parallel through exchange.'

But I have no idea what 'exchange' means in here.

Do we apply the cooling fields everytime we want to observe the ME switching?

Depends on if the switching is isothermal or not (which you now know what isothermal switching is), and that is why Prof Binek had the nature paper in 2010. Before that, no one had observed a back and forth switching of exchange bias electrically at constant temperature. People used to 'switch' it by warming it up and then cooling it down with the application of MEFC.

Are the cooling electric and magnetic fields same as the applied electric and magnetic field used to change the spin state of a magnetoelectric material?

Edited: I was wrong. MEFC was supposed to induced anisotropy in Cr2O3, which is to pre-align the domains. With pre-aligned domains, less energy is needed to switch them. However, if strong cooling fields are used, it helps to pin the domains and it requires more energy(higher switching fields) for switching. So, I don't think there is a definitely answer to this? Someone can help here. :-)

Hope it helps. :)

Chun

You may refer to magnetic cooling in Sec. 11.2 of ``Fundamentals of statistical and thermal physics'', written by F. Reif.