کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1810092 | 1525230 | 2013 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Magnetization and magnetic entropy change of a three-dimensional isotropic ferromagnet near the Curie temperature in the random phase approximation
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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
The behavior of a three-dimensional isotropic Heisenberg ferromagnet in the presence of a magnetic field H is investigated in the random phase approximation (RPA) near the Curie temperature Tc. It is shown that the magnetization M at the Curie temperature Tc is described by the law M(T=Tc)â¼H1/5 and the initial magnetic susceptibility Ï0 at temperatures Tâ¥Tc is given by Ï0(Tâ¥Tc)â¼(TâTc)â2. It means that in the RPA the critical exponents for a three-dimensional Heisenberg ferromagnet coincide with the critical exponents for the Berlin-Kac spherical model of a ferromagnet rather than with the critical exponents of the mean field approximation (MFA). Hence it follows as well that, when a magnetic field H is risen from H=0 to H=Ha, the magnetic entropy SM will be decreased as ÎSM(T=Tc)â¼âHa4/5 at the Curie temperature Tc and as ÎSM(T>Tc)â¼â(TâTc)â3Ha2 at temperatures T>Tc.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 416, 1 May 2013, Pages 29-32
Journal: Physica B: Condensed Matter - Volume 416, 1 May 2013, Pages 29-32
نویسندگان
E.E. Kokorina, M.V. Medvedev,