کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8154030 | 1524773 | 2018 | 22 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Enhanced magneto-caloric effect upon Co substitution in Ni-Mn-Sn thin films
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Mn rich Ni-Mn-Sn and Ni-Mn-Co-Sn alloy films were deposited on Si (1Â 0Â 0) substrate by dc magnetron sputtering from Ni50Mn37Sn13 alloy target at 1.8Â Pa Ar pressure with 70Â W dc power. Co was introduced by placing Co chips on the Ni-Mn-Sn target. As-deposited films were vacuum annealed at 823Â K for 1Â h. X-ray diffraction patterns of the films revealed modulated 14Â M structure of the martensite phase at room temperature. Magnetic entropy change (ÎSm) across the Curie temperature of the ferromagnetic films was estimated from initial isothermal magnetization curves using Maxwell's equation. ÎSm and refrigeration capacity (RC) of Ni-Mn-Sn and Ni-Mn-Co-Sn films increased with increasing film thickness. Upon Co substitution in Mn/Sn site(s), ÎSm and RC increased more remarkably. The change is more prominent in the case of 360Â nm films, wherein a 3.8-fold increase in ÎSM and 8.9-fold increase in RC was observed. Introduction of Co increased the magnetic moment and broadened the magnetic transition. These factors increased ÎSm and RC in Co substituted Ni-Mn-Sn alloy. Since TC shifted to higher temperatures with Co substitution, operating temperature of these magnetic refrigerants also shifted to higher temperature. This study indicates the possibility of developing high temperature cooling devices and waste energy harvesters using these films.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 448, 15 February 2018, Pages 146-152
Journal: Journal of Magnetism and Magnetic Materials - Volume 448, 15 February 2018, Pages 146-152
نویسندگان
Rajkumar Modak, M. Manivel Raja, A. Srinivasan,