Investigations of the temperature stability of constant magnets by the method of the Mössbauer spectroscopy

Abstract

548.0:539.17 M. S. Aliev, S. O. Shakhshaev, and S. V. LarinTo design magnetic devices intended for operation in different temperature regimes, the knowledge of the temperature coefficient of residual magnetization is required for the magnet used in the design. The temperature coefficient of residual magnetization α is determined from the formula [1]where 1 ( ) r M T is the residual magnetization of the magnet at the initial temperature 1 T ,is the change of the residual magnetization caused by the temperature change ∆T.In [2] we suggested methods for determining the degree of perfection of the magnetic texture and the constant of uniaxial magnetic anisotropy of particles of the powder constant magnets based on the Mössbauer spectroscopy. In the present study, a method for determining the coefficient α of constant magnets fabricated from BaFe 12 O 19 barium ferrite is suggested.As demonstrated in [2], when γ-rays propagate parallel to the magnet texture axis, the angle of scattering of the magnetic structure θ t and the relative magnetization of the magnet r s M M (where M r and M s are the residual magnetization and the saturation magnetization of the magnet, respectively) can be determined from relative areas of the Mössbauer spectrum of the sample. For two temperatures T 1 and T 2 , we can write [2] 1 1 1 1 cos ( ) ( ) 2 t r s M T M T =