title: Structure factor of model bidisperse ferrofluids with relatively weak interparticle interactions.
abstract: In the present manuscript we develop a theoretical approach to describe the pair correlation function of bidisperse magnetic dipolar hard- and soft-spheres. We choose bidisperse system as the first step to allow for polydispersity when studying thermodynamics of magnetic fluids. Using diagram technique we calculate the virial expansion of the pair correlation function up to the first order in density and fourth order in the dipolar strength. Even though, the radial distribution functions are extremely sensitive to the steric potential, we show that the behaviour of the isotropic centre-centre structure factor is almost indifferent to the type of the short-range repulsion. We extensively compare our theoretical results to the data of molecular dynamics simulations, which helps us to understand the range of validity of the virial expansion both on density and magnetic dipolar strength. We also investigate the influence of the granulometric composition on the height, width, and position of the structure factor first peak in order to clarify whether it is possible to extract structural information from experimentally measured small angle neutron scattering intensities.
authors: Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia.
authors: Ekaterina
authors: E
authors: Novak
authors: Institute for Computational Physics, Universiät Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors: Elena
authors: E
authors: Minina
authors: Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia.
authors: Elena
authors: E
authors: Pyanzina
authors: Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia.
authors: Sofia
authors: S
authors: Kantorovich
authors: Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia.
authors: Alexey
authors: A
authors: Ivanov
mesh_terms: D060328:Magnetic Phenomena; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D013816:Thermodynamics