(07A909) Reduction of hysteresis loss and large magnetocaloric effect in the C- and H-doped La(Fe, Si)_(13) compounds around room temperature

摘要

The effects of the interstitial C and H atoms on the phase formation, the hysteresis loss, and magnetocaloric effects of the NaZn_(13)-type La(Fe, Si)_(13) compounds are investigated. It is found that the annealing time to obtain a 1:13 structure is significantly reduced from 40 days for LaFe_(11.7)Si_(1.3) to a week for LaFe_(11.7)Si_(1.3)C_(0.2)- The introduction of C and H atoms can adjust Curie temperature to around room temperature and leads to the decrease in magnetic entropy change (ΔS_M) and magnetic hysteresis loss due to the weakening of itinerant-electron metamagnetic transition. Large — ΔS_M of 19.0 J/kg K at room temperature without hysteresis loss for LaFe_(11.7)Si_(1.3)C_(0.2)H_(1.7) is obtained for a field change of 5 T.