[01] A. V. Trukhanov, Department of Electronic Materials Technology, National University of Science and Technology MISiS, Moscow, Russia; Laboratory of magnetic films physics, SSPA “Scientific and practical materials research centre of NAS of Belarus”, Minsk, Belarus. [02] L. V. Panina, Department of Electronic Materials Technology, National University of Science and Technology MISiS, Moscow, Russia. [03] S. V. Trukhanov, Laboratory of magnetic films physics, SSPA “Scientific and practical materials research centre of NAS of Belarus”, Minsk, Belarus. [04] V. O. Turchenko, Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia. [05] I. S. Kazakevich, Laboratory of magnetic films physics, SSPA “Scientific and practical materials research centre of NAS of Belarus”, Minsk, Belarus. [06] M. M. Salem, Department of Electronic Materials Technology, National University of Science and Technology MISiS, Moscow, Russia.

The investigations of the crystal and magnetic structure by powder neutron diffractometry as well as the magnetic properties by vibration sample magnetometry for the BaFe_12-xAl_xO₁₉ (x=0.1-1.2) solid solutions have been performed at different temperatures and magnetic fields. The atomic coordinates and lattice parameters have been Rietveld refined. The Invar effect has been observed in low temperature range (from 150 to 4.2 K). It was explained by the thermal oscillation anharmonicity of atoms. The increase of microstress value with decreasing temperature has been defined from Rietveld refinement. The Curie temperature and change of total magnetic moment per formula unit have been defined for all the compositions of the barium hexaferrites BaFe_12-xAl_xO₁₉ (x=0.1-1.2) solid solutions. The magnetic structure model is proposed. The most likely reasons and the mechanism of magnetic structure formation are discussed.

Barium Hexaferrites, Neutron Diffraction, Crystal and Magnetic Structures

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