*Article* **Investigation of Magnetocaloric Properties in the TbCo2-H System**

**Galina Politova 1,2,\*, Irina Tereshina 3, Ioulia Ovchenkova 3, Abdu-Rahman Aleroev 3, Yurii Koshkid'ko 4, Jacek Cwik ´ <sup>4</sup> and Henryk Drulis <sup>4</sup>**


**Abstract:** In this work the magnetocaloric effect in the TbCo2-H system in the region of the Curie temperature was studied both by direct and indirect methods in external magnetic fields up to ~1.4 and 14 T, respectively. We have paid special attention to the magnetic and magnetothermal properties of the TbCo2–H with high hydrogen content. The mechanisms responsible for the change in the Curie temperature were established, and the field and temperature dependences of the magnetocaloric effect were analyzed in detail. In addition, the magnetocaloric properties (including critical parameters) for various systems based on the TbCo2 compound were compared. The main regularities of the change in the MCE value and the Curie temperature depending on the composition are discovered and discussed.

**Keywords:** rare-earth intermetallic compound; Laves phase structure; hydride; magnetic phase transition; magnetocaloric effect
