Magnetic Structures of Some Multiferroics
We studied crystal and magnetic structures of some composite and single-phase multiferroics: (x)MFe2O4 + (1-x)BaTiO3, Ni3-yCoyV2O8, and Bi0.9Ba0.1Fe0.9Ti0.1O3. Composite multiferroics (x)MFe2O4 + (1-x)BaTiO3 with x = (0.2; 0.3; 0.4) and M = (Ni, Co) have ferrimagnetic structure, which is described by the propagation vector k = 0. Oxides Ni3-yCoyV2O8 with y = (0.1; 0.3; 0.5) possess a modulated magnetic structure, described by the vector k = (δ, 0, 0), where δ = 0.283 and 0.348 at 7.4 K for y = 0.1 and 0.5, respectively. In the Bi0.9Ba0.1Fe0.9Ti0.1O3 multiferroic a magnetic order is destroyed at 600 K and the Fe-ion magnetic moment decreases from µ = 3.46(5) μB at 300 K to zero at 600 K.
 Lee. Choi Semkin, Teplykh Skryabin Li Pirogov Temperature dependence of the propagation vector, in in Ni3-xCoxV2O8 with x=0.1 and, 397–225, 225-229, 397, 2016.
 Y. Liu, Y. Wu, D. Li, Y. Zhang, J. Zhang, and J. Yang, A study of structural, ferroelectric, ferromagnetic, dielectric properties of NiFe2O4-BaTiO3 multiferroic composites, Journal of Materials Science: Materials in Electronics, 24, no. 6, 1900–1904, (2013).
 Kumar. Ortega, Scott Katiyar Multifunctional magnetoelectric materials for device applications, J. Phys.: Condens. Matter, 27, Article ID 504002, (2015).
 D. I. Khomskii, Multiferroics: Different ways to combine magnetism and ferroelectricity, Journal of Magnetism and Magnetic Materials, 306, no. 1, 1–8, (2006).
 Cheong. Mostovoy, Multiferroics: a magnetic twist for ferroelectricity, Nat. Mater, 6, 13–20, (2007).
 J. Rodríguez-Carvajal, Recent advances in magnetic structure determination by neutron powder
diffraction, Physica B: Physics of Condensed Matter, 192, no. 1-2, 55–69, (1993).
 Fuess. Bertaut Pauthenet, Durif Structure aux rayons X, neutrons et proprietes magnetiques des orthovanadates de nickel et de cobalt, Acta Cryst, Sect B: Struct. Crystallogr. Cryst. Chem, 26, 2036– 2046, (1970).
 Lee. Fernandez-Diaz Kimura Noda, Negative magnetostrictive magneto electric coupling of BiFeO3, Phys. Rev. B, 88, Article ID 060103, (2013).