TY - JOUR
T1 - Microstructure and isothermal magnetic entropy change of La(Fe 0.89Si0.11)13 in a single-phase formation process by annealing
AU - Fujieda, S.
AU - Fukamichi, K.
AU - Suzuki, S.
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Young Scientists (B), No. 23760620, from the Japan Society for the Promotion of Science. The author (S.F.) acknowledges useful discussions on the La(Fe 0.89 Si 0.11 ) 13 system with A. Fujita.
PY - 2013/6/25
Y1 - 2013/6/25
N2 - By annealing at 1323 K, the single-phase formation process of La(Fe 0.89Si0.11)13 with a cubic NaZn 13-type structure was investigated. A dendritic microstructure composed of an α-Fe phase with a mean size of about 10 μm and a LaFeSi phase in the as-solidified state is completely changed into the NaZn 13-type single-phase by annealing for 300 h. The growth of the NaZn13-type phase is steep up to an annealing time ta = 100 h, and then becomes sluggish. As a result, the maximum isothermal magnetic entropy change, ΔSmmax, markedly increases with increasing ta up to 100 h in response to the formation of the NaZn13-type phase. In addition, the position of ΔSmmax shifts to higher temperature ranges due to the increase of the Curie temperature TC. Accordingly, thorough annealing for the single-phase formation of La(FexSi 1-x)13 is important for high-performance magnetic refrigerants.
AB - By annealing at 1323 K, the single-phase formation process of La(Fe 0.89Si0.11)13 with a cubic NaZn 13-type structure was investigated. A dendritic microstructure composed of an α-Fe phase with a mean size of about 10 μm and a LaFeSi phase in the as-solidified state is completely changed into the NaZn 13-type single-phase by annealing for 300 h. The growth of the NaZn13-type phase is steep up to an annealing time ta = 100 h, and then becomes sluggish. As a result, the maximum isothermal magnetic entropy change, ΔSmmax, markedly increases with increasing ta up to 100 h in response to the formation of the NaZn13-type phase. In addition, the position of ΔSmmax shifts to higher temperature ranges due to the increase of the Curie temperature TC. Accordingly, thorough annealing for the single-phase formation of La(FexSi 1-x)13 is important for high-performance magnetic refrigerants.
KW - Annealing time
KW - Magnetic entropy change
KW - Magnetic refrigerant
KW - Microstructure
KW - Single-phase
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U2 - 10.1016/j.jallcom.2013.03.036
DO - 10.1016/j.jallcom.2013.03.036
M3 - Article
AN - SCOPUS:84875948269
SN - 0925-8388
VL - 566
SP - 196
EP - 200
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -