Russian scientists managed to develop a series of rare-earth metal alloys, which in the future will make it possible to abandon the use of freon or any other refrigerant in refrigerators. The principle of their work lies in the ability to both absorb heat and to release it under the influence of a magnetic field. Initially, the task that was set before scientists was to create a refrigerator for use in space stations. Moreover, it should have a small mass, but high efficiency and work without the use of gas. Now we can safely say that in the near future the development will allow creating such cooling units on a magnet for their use in home life.
What are these rare earth metals that can replace unsafe freon? By the method of numerous tests, scientists still managed to find the optimal combination for magnetic cooling from gadolinium, terbium, dysprosium, holmium and cobalt. Since metals are expensive (they cost the same as silver), I had to work on how to reduce their cost. They searched for solutions since the 1960s and found it in aluminum. The researchers proposed to include this material in the composition of the alloys, since it is capable of not only preserving the properties of rare-earth metals, but also significantly improving them.
How will the cooling system work in a magnetic refrigerator? Alternatively, scientists suggest using a spinning wheel with sections containing the combination of metal alloy itself and a permanent powerful magnet. During the rotation of the wheel, the alloy passes through the magnet and heats up. The resulting heat is removed by a heat exchanger, which is cooled by water. Leaving the zone of action of the magnet, the alloy, on the contrary, cools. In this case, the temperature in the heat exchanger decreases, therefore, the second water stream continuously circulating in it is also cooled. It is the latter that is needed to maintain the cold in the chambers of the refrigerator on a magnet.
Scientists argue that refrigerators using a magnetic field for cooling are more efficient and quieter than devices that use freon. Of course, they still have to work on solving the problem of the heterogeneity of the temperature distribution in the chambers, and also to check the reliability and stability in operation of the alloy itself. But since scientists from Europe, the United States and Japan are also working on the creation of a magnetic refrigerator, in addition to Russian researchers, one can be sure that all the shortcomings of the magnetic cooling technology will be eliminated in the near future.