| 1 | A new scale for optimized cryogenic magnetocaloric effect in ErAl_2@Al_2O_3 nanocapsules显示文摘The Er Al_2@Al_2O_3nanocapsules with Er Al_2core and Al_2O_3shell were synthesized by modified arc-charge technique.The typical core-shell structure of the nanocapsules was confirmed by high resolution transmission electron microscopy and X-ray photoelectron spectroscopy.Transmission electron microscopy analysis shows the irregular sphere of the nanocapules with an average diameter of 26 nm.Magnetic investigation revealed the Curie temperature of Er Al_2@Al_2O_3nanocapsules at 20 K and the typical superparamagnetic behavior between blocking temperature and Curie temperature.Based on the blocking temperature and average diameter,the magnetocrystalline anisotropy constant of Er Al_2@Al_2O_3nanocapsules was estimated to illustrate the magnetic contribution to the-S_M.The large-S_Mof 14.25 J/(kg K)was obtained under 50 k Oe at 5 K.A vital parameterˇwas introduced in the present work to scale the optimized magnetic characteristics and the optimized mechanism was discussed in detail according to classical superparamagnetic theory.The results demonstrate that the optimal-S_Mwill be obtained when the magnetic parameterˇis close to the theoretical coefficient. | F.Wei S.Ma L.Yang Y.Feng J.Z.Wang A.Hua X.G.Zhao D.Y.Geng Z.D.Zhang | 2018 | Journal of Materials Science & Technology2018，34，5： | 0 |
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