A technology that has the potential to create more efficient and compact refrigeration devices is an Active Magnetic Regenerative Refrigerator (AMRR). An AMRR can operate over a broad range of temperatures, as long as the appropriate refrigerant is implemented. Thus this flexible technology can be used for small, efficient, and simple room temperature refrigerators, as well as efficient gas liquefaction plants (AMRLs). Active Magnetic Regenerator Refrigeration exploits the magnetocaloric effect displayed by magnetic materials whereby a reversible temperature change is induced when the material is exposed to a magnetic field. By using the magnetic materials in a regenerator as the heat storage medium and as the means of work input, one creates an Active Magnetic Regenerator (AMR).

In this work, an experimental study of Active Magnetic Regenerators composed of single and multi-materials is carried out. AMRs made up of Gd, Gd_.74Tb_.26, and Gd_.85Er_.15 are studied in cycles rejecting heat between 270 K and 311 K. A variety of operating conditions were tested and regenerator performance with respect to heat load, utilization, and frequency was examined. AMR behavior was qualitatively interpreted and a path for performance improvement and future investigations laid.