Surface and bulk magnetic anisotropy in amorphous TbFe/SiN trilayered films

Abstract

Absarrd--Mognetic perpendicular anisotropy constants of RF-sputtered amorphous TbFe thin films were measured by VSM and mngnetwptic techniques. Anisotropy depended heady 011 fUm thickness. We have found that the spontaneous magnetization changed with thickness in the same fashion as in the presence of a very thin (1 mu) highly magnetized interface layer. Msotropy measured from the top and bottom Alm surfaces revealed very different dependence on the deposition panmeten Because the magnetization reversal is incoherent due to the different anisotropy fields in the surface layers and in the bulk, it is necessary to account for the reversal mechanism to evaluate the true value of intrinsic anisotropy of the amorphous alloy.

Selective-Resputtering-Induced Perpendicular Magnetic Anisotropy in Amorphous TbFe Films

“…This rollover is due to the increase in thermalizing collisions experienced by the Ar ions/neutrals in the plasma, which acts to decrease the number of Ar ions/neutrals that possess sufficient energy to resputter at the film surface. In this later curve, our data are plotted with the data of Kavalerov et al [21], who previously measured the working gas-pressure dependence of magnetic anisotropy in rf magnetron-sputtered a-TbFe, and reported a similar behavior.…”

“…In a-TbFe this results in a large volume-averaged magnetic anisotropy energy, as large as 10 7 erg͞cm 3 [9], which is strongly dependent upon the parameters used in processing [10][11][12]. Empirical relationships between the magnetic anisotropy energy and the deposition temperature [19,20], working gas pressure [21], and stress [6], have been investigated in a-TbFe films. Cheng et al [6] showed that the stress state of the film was responsible for only a fraction of the magnetic anisotropy.…”