کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5490303 | 1524788 | 2017 | 33 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Sodium - Deficiency effects on the structural, magnetic and magnetocaloric properties of La0.8Na0.2âxâ¡xMnO3 (0 â¤Â x â¤Â 0.15)
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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
In this paper, we report the magnetocaloric effect of Na vacancies in La0.8Na0.2âxâ¡xMnO3 (0 â¤Â x â¤Â 0.15) powder samples synthesized using the sol-gel technique. Structural investigations using X-ray diffraction show that all the elaborated compounds crystallise in the rhombohedral structure with R3¯c space group. Magnetic measurements versus temperature reveal a magnetic transition from ferromagnetic (FM) to paramagnetic (PM) phase when increasing temperature. The Curie temperature TC shifts to lower values with increasing sodium-deficiency. The Arrott plots indicate that a second order phase transition takes place. The effect of sodium-deficiency on the magnetocaloric properties has also been investigated. The maximum values of the magnetic entropy changes, |âÎSM|max, under a magnetic field change of 5T are found to be 4.74; 4.13; 6.14 and 4.55 J/kg K for x = 0; 0.05; 0.1 and x = 0.15 respectively. The relative cooling power (RCP) and its field dependence are also analyzed. The obtained magnetic entropy changes are compared to calculated ones based on the Landau theory and a good concordance is observed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 433, 1 July 2017, Pages 239-247
Journal: Journal of Magnetism and Magnetic Materials - Volume 433, 1 July 2017, Pages 239-247
نویسندگان
S. Choura-Maatar, R. M'nassri, W. Cheikhrouhou-Koubaa, M. Koubaa, A. Cheikhrouhou, E.K. Hlil,