Structure and magnetic properties of etched NiFeCo films

Abstract

The effect of chemical etching on the surface relief of NiFe and NiFeCo films and their magnetic parameters is studied. Electron micrograph analysis shows that during the etching inhomogeneities in the film thickness appear with a period of about 1000 A and an amplitude of the thickness fluctuations of about 100 A. This process goes along with the increase of the angular amplitude of the magnetization ripple and coercivity and is well described by Hoffmann's theory. The coercive force component stipulated by pinning of the domain walls on localized defects does not change significantly during the etching. Der EinfluD des chemischen Atzvorgangs auf das Oberflachenrelief und die magnetischen Parameter von NiFe-und NiFeC0:Schichten wird untersucht. Elektronenmikroskopische Untersuchungen zeigten, daD beim Atzen Schichtdickeninhomogenitaten mit einer Periode von ca. 1000 A und Dickenanderungen von etwa 100 A entstehen. Dieser Vorgang ist begleitet von einem Anwachsen der Ripple-Winkelamplitude und der Koerzitivitat. Er 1aBt sich mit der Hoffmannschen Theorie gut beschreiben. Die durch das Haften der Befeichsgrenzen an ortsfesten Fehlstellen bedingte Koerzitivkraftkomponente zeigt wahrend des Atzens keine merkliche Veranderung.

Surface/interface-roughness-induced demagnetizing effect in thin magnetic films

“…Nonetheless, how does the detailed morphology of the surface affects the apparent coercivity was not considered in most experiments. [6][7][8]10 Only a few experiments relate the change in coercivity to the change of the interface width w. Recently, some detailed works have been performed. 5,9 Experiments of Co films: In the following we shall discuss the connection of our theory and our experimental work.…”

“…One kind is a film with a single rough boundary. [5][6][7] For example, Jiang et al studied the relation of the coercivity versus surface roughness of Co ultrathin films deposited on an atomically flat Cu substrate. 5 Vilain et al investigated the coercivity versus surface roughness of electrodeposited NiCo alloy films, 6 and Malyutin, et al showed that the coercivity of chemically etched Ni-Fe-Co films increases with the surface roughness.…”

“…5 Vilain et al investigated the coercivity versus surface roughness of electrodeposited NiCo alloy films, 6 and Malyutin, et al showed that the coercivity of chemically etched Ni-Fe-Co films increases with the surface roughness. 7 Very recently, Freeland et al using the x-ray resonant magnetic scattering studied hysteretic behavior of CoFe thin films with varying roughness. 8 They also found the coercivity increased with the surface roughness.…”

Effects of Surface Topography on Magnetization Reversal of Magnetic Thin Films

“…[2][3][4] For example, Jiang et al 2 studied the relation of the coercivity versus surface roughness of Co ultrathin films deposited on an atomically flat Cu substrate. Vilain et al 3 investigated the coercivity versus surface roughness of NiCo alloy films and Malyutins et al 4 showed that the coercivity of chemically etched Ni-Fe-Co films increases with the surface roughness. Frealnd et al 5 studied hysteretic behavior of CoFe thin films with varying roughness using the X-ray resonant magnetic scattering.…”

Roughness effects on magnetic properties of thin films

“…[1]. For NiFeCo "lms the coercivity increased with increasing surface roughness [2]. For Co "lms deposited on plasma etched Si(100) substrates, the uniaxial anistropy decreased and disappeared for the roughest "lms.…”