As an alternative to systems with semiconductor modules, a number of research teams are considering the possibility of using the caloric effect in various ways of its manifestation, as well as ways to implement it in promising compact products.
It should be noted that a special case of the caloric effect is the magnetocaloric effect – a change in the temperature of magnetic substances under conditions of a change in the external magnetic field. In particular, it is possible to noticeably reduce the temperature of some materials by placing them in strong magnetic fields. One of these materials is the well-known Mn3SnC compound among researchers, which, by the way, belongs to the class of perovskites, which are extremely promising materials for many areas of science and technology.
Unfortunately, the need to use fields with a strength of 2 T and higher significantly limits the scope of such solutions. This is primarily due to the fact that such a strong magnetic field requires very expensive and very bulky magnets. It is currently technically difficult and economically impractical to implement them in compact products. Indeed, the generation of powerful magnetic fields requires a significant amount of energy. In addition, such fields are often poorly compatible with many electronic components, disrupting their correct operation.
Another variant of the caloric effect is the electrocaloric effect – a noticeable change in the temperature of substances under the influence of strong electric fields. The effect is observed in a number of ferroelectric materials, including polymers. Of the most popular among researchers, as in the previous version, are minerals with a perovskite-type structure.
And recently, Chinese scientists have shown that applying an appropriate voltage to a specially designed composite material using an electric field causes a large and reversible caloric effect. This is achieved by combining the Mn3SnC layer with a piezoelectric lead zirconate titanate (PZT) layer. It should be noted that this phenomenon has not yet been fully studied and therefore has not been adequately explained. However, the researchers believe that the change in temperature is caused by the distortion of the structure of the base material by the piezoelectric layer.
A new way to enhance the thermal effect without the use of strong fields could open up new possibilities for solid-state cooling and ultimately lead to more energy efficient and lighter, and in the future, less expensive refrigerators for various applications. But all this is a topic for a completely different article. We will be patient and will closely monitor the results of research. No doubt it will be interesting!
Published on 16.02.2023
