Magnetic refrigerant compositions and processes for making and using

A magnetic process comprising:

• subjecting a magnetically susceptible media to a magnetic field wherein the media is magnetized and the magnetized media absorbs the heat of magnetization;
• transferring the absorbed heat from the magnetized media to a heat sink;
• removing the magnetized media from the magnetic field, wherein the magnetic media undergoes spontaneous cooling to produce a cooled magnetic media;
• and providing heat to the cooled magnetic media from a heat source, wherein said process is accomplished at about 275 degrees Kelvin, and wherein the magnetically susceptible media is a liquid or solid dispersion of a nanocomposite comprising from about 0.001 to about 60 weight percent of magnetic nanocrystalline metal oxide particles and from about 40 to about 99.999 weight percent of an ion exchange matrix, and optionally a liquid carrier or heat transfer fluid in an amount of from about 1 to about 99 weight percent based on the weight of the nanocomposite.