Magnetostatic Energy Associated with Variation of Local Magnetization Direction in Field Annealed Amorphous Ribbons

I. Ciobotaru, N. Rezlescu, R. Anghelache
1997 Acta Physica Polonica. A  
It is shown that in field annealed amorphous ribbons (with oblique intrinsic anisotropy), the magnetostatic energy associated with spatial fluctuations of the local magnetization depends on the magnetization state. The corresponding magnetostatic interactions can play an important part in the magnetic behaviour of the amorphous ribbons with small macroscopic anisotropy. PACS numbers: 75.50.Kj Some amorphous ribbons show distinct magnetic properties due to their small macroscopic anisotropy. In
more » ... pic anisotropy. In the amorphous samples, the magnetocrystalline anisotropy is absent but the magnetoelastic anisotropy, the unidirectional order or the shape effect can play an important part. Still another characteristic is the fluctuation of the magnetic moment around the average magnetization f the magnetic domain [1, 2] MD. Since the divergence of the vector of local magnetization M is not zero, magnetostatic interactions between the neighbouring regions of the sample will be present. These interactions can play an important part in the domain pattern formation in the case of longitudinal anisotropy [3], as well as in the magnetic and magnetoelastic behaviour of the amorphous ribbons in low field [4] . The aim of this paper is to calculate the density of the magnetostatic energy E" associated to the volume poles density in amorphous ribbons with oblique anisotropy. For this, we shall start from the general formula for a rectangular sample with the thickness 2d and the periodic variation of the magnetization in the sample plane [5] where p0 is the free space permeability, k is the wave vector in the ribbon plane and Mk are the Fourier coefficients. The problem consists in adopting a model related to the local magnetization orientation and the calculus of the Fourier coefficients. (427)
doi:10.12693/aphyspola.91.427 fatcat:oxfzmp3en5e6doqh7c5aol7riu