کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5438329 1398183 2017 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure, magnetocaloric and critical properties of layered La2Sm0.4Sr0.6Mn2O7 perovskite
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Structure, magnetocaloric and critical properties of layered La2Sm0.4Sr0.6Mn2O7 perovskite
چکیده انگلیسی

We report the structure, magnetocaloric effect, and critical phase transition in the manganite La2Sm0.4Sr0.6Mn2O7 (LSSMO) synthesized by a sol-gel method. X-ray diffraction together with Rietveld refinement show that the sample crystallizes in a Sr3Ti2O7-type tetragonal structure with a space group of I4/mmm. This compound undergoes a second-order ferromagnetic (FM) to paramagnetic phase transition at TC=348 K and shows strong FM properties below the TC. Based on the data of isothermal magnetization measured around the TC and Maxwell's relation, we calculated the maximum magnetic entropy change (-ΔSMmax) to be 4.69 J kg−1 K−1 and the relative cooling power to be 233.9 J kg−1 for a μ0ΔH=5 T magnetic field variation. These results indicate that LSSMO can be considered as a potential candidate material for application in magnetic refrigeration above room temperature. The critical behavior near the TC was studied through the analysis of the magnetic field dependence of the magnetic entropy change and Widom's scaling relation. The exponent values estimated in this work are fairly close to those theoretically predicted by mean field theory (β=0.5, γ=1.0, and δ=3.0), revealing that long-range FM ordering exists in LSSMO. Scaling law theory also confirms the validity of the deduced critical exponents.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 43, Issue 12, 15 August 2017, Pages 8709-8714
نویسندگان
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