Tunable magnetocaloric effect at approximately room temperature by Y-substitution in Ho2Fe17

The structure, magnetic transition and magnetocaloric effect of the intermetallic compounds (Ho2-xYx)Fe17 (x = 0, 0.5, 1 and 1.5) were investigated. The compounds crystallize into a Th2Ni17-type structure with the P63/mmc space group, as determined by Rietveld refinement of the XRD powder diffraction patterns. All the samples undergo a second-order magnetic transition from the ferromagnetic to paramagnetic state, and the Curie temperature decreases from 334 K (x = 0) to 314 K (x = 1.5) with increasing Y content. In the paramagnetic region, the reciprocal magnetic susceptibilities chi- 1 for (Ho2-xYx)Fe17 (x = 0.5, 1 and 1.5) obey the Curie-Weiss law. The effective magnetic moment was determined to be 28.97 mu B/f.u., 32.88 mu B/f.u. and 33.78 mu B/f.u., respectively, with corresponding paramagnetic Curie temperatures of 323 K, 308 K and 304 K. The maximum magnetic entropy changes for (Ho2-xYx)Fe17 (x = 0, 0.5, 1 and 1.5) are 3.0 J/kg K, 3.5 J/kg K, 3.8 J/kg K and 4.6 J/kg K, with corresponding refrigerant capacity values of 168 J/kg, 197 J/kg, 263 J/kg and 342 J/kg for a field change of 0-5 T. The tunable Curie temperature and considerable magnetocaloric effect indicate that (Ho2-xYx)Fe17 (x = 0, 0.5, 1 and 1.5) compounds are candidates for room-temperature magnetic refrigerants.

Automated summary

The structure, magnetic transition, and magnetocaloric effect of (Ho2-xYx)Fe17 (x = 0, 0.5, 1, and 1.5) intermetallic compounds were investigated. The results showed that these compounds have a tunable Curie temperature and considerable magnetocaloric effect, making them potential candidates for room-temperature magnetic refrigerants.