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Author Vuong, Van Hiep ♦ Do Thi, Kim Anh ♦ Thuan Nguyen, Khac ♦ Nhat Hoang, Nam ♦ Le, Van Hong
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ BINARY ALLOY SYSTEMS ♦ COMPARATIVE EVALUATIONS ♦ COOLING ♦ CURIE POINT ♦ ELECTRONS ♦ ENTROPY ♦ LANTHANUM ALLOYS ♦ MAGNETOSTRICTION ♦ PRESSURE RANGE GIGA PA ♦ STOICHIOMETRY ♦ TEMPERATURE RANGE 0273-0400 K
Abstract The La-excess alloys La{sub 1+δ}(Fe{sub 0.85}Si{sub 0.15}){sub 13} (δ = 0.06 and 0.09) exhibit large magnetocaloric effect which has been attributed to the occurrence of itinerant-electron metamagnetic transition near the Curie temperature T{sub C}. The maximum entropy change −ΔS{sub m} was shown to be from 4.5 to 11.5 J/kg K for the applied field variation ΔH from 20 to 70 kOe, respectively. The estimated relative cooling power for ΔH = 70 kOe was 418 J/kg. The alloys show a typical NaZn{sub 13}-type cubic structure, featuring a doping-induced magnetovolume effect with the increase in T{sub C}. Under the applied pressure up to 2 GPa, the T{sub C} as deduced from resistance measurements decreased linearly, ΔT{sub C} = 113 (for δ = 0.06) and 111 K (for δ = 0.09), together with a corresponding decrease of resistivity, Δρ = 6.1 μΩ m at room temperature for both samples. At a low pressure, the effect of spontaneous magnetostriction on T{sub C} caused by applying the pressure appeared to have a similar magnitude to that of the negative magnetovolume effect caused by La-excess doping. In comparison with other stoichiometric La(Fe{sub 1−x}Si{sub x}){sub 13} compounds, the pressure in our case was shown to have a smaller influence on T{sub C}.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-10-14
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 120
Issue Number 14


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