| Autor: |
Van Hiep Vuong, Kim Anh Do Thi, Khac Thuan Nguyen, Van Hong Le, Nam Nhat Hoang |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2016, Vol. 120 Issue 14, p1-6, 6p, 1 Diagram, 1 Chart, 4 Graphs |
| Abstrakt: |
The La-excess alloys La1+δ(Fe0.85Si0.15)13 (d=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 TC. The maximum entropy change -ΔSm 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 NaZn13-type cubic structure, featuring a doping-induced magnetovolume effect with the increase in TC. Under the applied pressure up to 2 GPa, the TC as deduced from resistance measurements decreased linearly, ΔTC=113 (for δ=0.06) and 111K (for δ=0.09), together with a corresponding decrease of resistivity, Δp=6.1 µΩ m at room temperature for both samples. At a low pressure, the effect of spontaneous magnetostriction on TC 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(Fe1-xSix)13 compounds, the pressure in our case was shown to have a smaller influence on TC. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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