Wall Transitions and Coupling of Magnetization in NiFe/C/NiFe Double Films

Abstract

AS^) (a), H. NIEDOBA (a), M. RUHRIC (b), G. WITTMANN (b), A. HUBERT (b), H. 0. GUPTA (a), L. J. HEYDERMAN4) (a), and I. B. PUCHALSKA (a)Magnetic double films separated by a non-magnetic layer are investigated, which were prepared by electron beam evaporation. Transitions between superimposed Nee1 walls and twin N M walls with quasi-walls, triggered by application of an in-plane magnetic field following the hard direction of magnetization, are studied theoretically. The computed results are compared with experiments on NiFe/C/NiFe double films and a good agreement is achieved if the magnetic coupling between the films of NiFe is assumed to increase with increasing film thickness. An original determhahon method for the coupling strength in ferromagnetically coupled films, based on the measurement of the twin wall separation, is developed.Durch Elektronenstrahlverdampfung hergestellte magnetische Doppelschichten werden untersucht, die durch eine nichtmagnetische Zwischenschicht getrennt sind. In solchen Schichtsystemen gibt es zwei Arten von 180"-Wanden, antiparallel iiberlagerte Neehande und parallel eusgerichtete Zwillingswande. Der Ubergang zwischen beiden Formen in einem Magnetfeld entlang der schweren Richtung wird berechnet und mit Beobachtungen an Schichten des NiFe/C/NiFe-Systems verglicben. Gute obereinstimmung zwischen Theorie und Experiment wird erzielt, wenn angenommen wird, daB sich die (ferromagnetische) Kopplung zwischen den Schichten mit zunehmender NiEe-Schichtdicke verstarkt. Die Vermessung des Abstandes zwischen Wand und Quasiwand in den Zwillingswiinden envies sich zusammen mit der numerischen Simulation als empfindliche Methode zur Messung der Kopplungskonstanten in ferromagnetisch gekoppelten Doppelschichten. I) 1 place A.

Role of magnetostatic interactions in micromagnetic structure of multiferroics

“…In this regard, it is interesting to note that the observation of magnetostatic coupling between domain walls has been well documented in magnetic multilayers. [22][23][24][25][26][27] However, its observation in bulk magnetic materials is new, and the stacked twin plates can be considered to be a natural structural analog to synthetic multilayers.…”

Cooperative motion of domain walls in magnetic multilayers

“…The stray fields emanating from a Néel wall creates a magnetic disturbance in adjacent layers, causing their magnetization to locally rotate relative to the magnetization profile within the Néel wall, giving rise to so-called quasi-Néel walls; see Ref. [38,[43][44][45][46][47][48][49][50] and references within for structure, energy, and observation of twin walls. This is shown, for example, in a 3 TbFe/FeCo multilayer in Fig.…”