TY - JOUR
T1 - Influence of homogenization of microstructual composition on hydrogen absorption into La(FexSi1-x)13 magnetic refrigerants
AU - Fujieda, S.
AU - Fujita, A.
AU - Fukamichi, K.
AU - Suzuki, S.
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Scientific Research (B), no. 20360289, from the Japan Society for the Promotion of Science; in part by Tohoku University’s Hatano Fund; and in part by the grant project of the Research Center for Sustainable Science and Engineering in IMRAM and the Mazda Foundation.
PY - 2011/10
Y1 - 2011/10
N2 - The Curie temperature TC of La(Fe0.89Si 0.11)13 in inhomogeneous and homogeneous (single phase) states is controlled by heat treatment and hydrogen absorption. The magnetization change at TC around room temperature of the inhomogeneous specimens composed of α-Fe, LaFeSi, and La(Fe xSi1-x)13 phases becomes sluggish after hydrogen absorption, because TC in the specimens has a distribution accompanied by some inhomogeneity of the hydrogen content. As a result, the magnitude of the isothermal magnetic entropy change Δ Sm due to the itinerant-electron metamagnetic transition of these specimens is decreased by hydrogen absorption. On the other hand, the magnitude of Δ S m after hydrogen absorption into the single-phase specimen is almost the same as that before hydrogen absorption. Consequently, the compositional homogenization in La(FexSi1-x)13 is necessary to obtain large magnetocaloric effects around room temperature.
AB - The Curie temperature TC of La(Fe0.89Si 0.11)13 in inhomogeneous and homogeneous (single phase) states is controlled by heat treatment and hydrogen absorption. The magnetization change at TC around room temperature of the inhomogeneous specimens composed of α-Fe, LaFeSi, and La(Fe xSi1-x)13 phases becomes sluggish after hydrogen absorption, because TC in the specimens has a distribution accompanied by some inhomogeneity of the hydrogen content. As a result, the magnitude of the isothermal magnetic entropy change Δ Sm due to the itinerant-electron metamagnetic transition of these specimens is decreased by hydrogen absorption. On the other hand, the magnitude of Δ S m after hydrogen absorption into the single-phase specimen is almost the same as that before hydrogen absorption. Consequently, the compositional homogenization in La(FexSi1-x)13 is necessary to obtain large magnetocaloric effects around room temperature.
KW - Homogenization
KW - hydrogen absorption
KW - itinerant-electron metamagnetic transition
KW - magnetocaloric effects (MCEs)
KW - microstructure
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U2 - 10.1109/TMAG.2011.2157092
DO - 10.1109/TMAG.2011.2157092
M3 - Article
AN - SCOPUS:80053534880
SN - 0018-9464
VL - 47
SP - 2459
EP - 2462
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 10
M1 - 6027627
ER -