Nanoscale physics

Magnetic and structural features of Sr2FeMoO6- (SFMO) double perovskite near Curie temperature
Krupa M.M.1, Коnоplyuк S.М.1, Kalanda M.A.2, Demianov S.E.2
1 Institute of Magnetism of NASU and MESU. Vernadsky blv., 36-b, Kyiv-03680, Ukraine. 
E-mail: ksm@imag.kiev.ua 
2 Scientific-Practical Materials Research Centre of the National Academy of Sciences of Belarus, P.Brovka Str.19, 220072, Minsk, Belarus

   The Sr2FeMoO6 (SFMO) metal-oxide compound is known as prospective one for spintronics applications with additional advantages such as high values of the Curie temperature, large magnetoresistance, high sensitivity to the magnitude and orientation of the magnetic field, good temperature and chemical stability [1,2]. In this work, Sr2FeMoO6–δ polycrystalline samples with different oxygen content were synthesized by the solid-phase technique to study the influence of oxygen on formation of their crystalline structure and magnetic ordering. 
   XRD examination showed that degree of superstructural ordering in arrangement of iron and molybdenum cations decreased with amount of oxygen in the compound. Magnetization measurements revealed occurrence of magnetic transition between ferromagnetic and paramagnetic states at temperatures about 430 K. It is also found that superstructural ordering promotes stability of ferromagnetic phase increasing Curie temperature and saturation magnetization. The estimation of magnetocaloric effect near Curie temperature from the isothermal magnetization curves demonstrates that strontium ferromolybdate is a promising material for magnetic refrigeration. 

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2.	Sarma D.D., Mahadevan P., Saha-Dasgupta T., Ray S., Kumar A. Electronic Structure of Sr2FeMoO6// Phys Rev Lett.-2000.-85, N 12.-P.  2549-2552.