**3.4 The Spanish device**

The device shown in Fig. 6 was developed by the team of the Polytechnic University of Catalonia in Barcelona (Allab, 2008). The magnetocaloric material is a ribbon of gadolinium (Gd 99.9%) fixed on a plastic disc and immersed in a fluid (olive oil). The magnetic cycle of magnetization / demagnetization is provided by the rotation of the plastic disc and its interaction with a magnet. The temperature span is obtained respectively: 1.6 and 5 K for a magnetic field of 0.3 T and 0.95 T. This corresponds to 2.5 times the MCE of Gd. Even if obtained performances of this system were weak, this device is the first that has shown the feasibility of magnetic refrigeration with fields accessible by permanent magnets.

Fig. 6. The Magnetic device made in Spain (Bohigas, 2000).
