For students

Supervisor: dr hab. Jacek Ćwik

Contact data:  

Description:

Hydrogen is rapidly becoming the preferred type of fuel; however, its liquefaction using today’s vapor-compression technology is energy‑intensive and costly. Magnetic cooling based on the magnetocaloric effect (MCE) is an energy‑efficient and environmentally friendly alternative, but improving the refrigerant materials is crucial for its success. The magnetic refrigeration method can be applied over a wide temperature range, from very low temperatures up to several hundred Kelvin. An ideal magnetic refrigerant should exhibit sufficiently high magnetocaloric properties across the entire operating temperature range of the system.

The proposed PhD project will involve medium‑ and high‑field magnetic studies of intermetallic lanthanide compounds with the Laves phase structure, i.e., R(Ni_1‑xAl_x)₂ (where R represents selected lanthanides and 0.0 ≤ x ≤ 1.0), with the aim of proposing a multilayer magnetic magnetocaloric material for cryogenic applications. The selected parent compounds forming the basis of the proposed solid solutions display second‑order magnetic phase transitions and exhibit large reversible magnetocaloric effects in the cryogenic temperature range due to the unique properties associated with the highly localized magnetic moments originating from the incompletely filled 4f‑electron shell of rare‑earth atoms, while the Ni and Al atoms in these compounds remain nonmagnetic.

The conducted research will make it possible to propose magnetic refrigerants that may be used in multilayer materials characterized by suitably high, nearly constant MCE values over a broad temperature range.