Magnetism of Fe/V and Fe/Co multilayers

Eriksson, Olle; Bergqvist, Lars; Holmström, Erik; Bergman, Anders; Lebacq, O.; Frota-Pessôa, S.; Hjörvarsson, Bjørgvin; Nordström, Lars

doi:10.1088/0953-8984/15/5/313

Cited by 31 publications

(16 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been successfully applied to study multilayers [27][28][29], substitutional and interstitial impurities and clusters in metallic hosts [30][31][32], metallic surfaces [16,33], as well as impurities and defects embedded in metallic surfaces [17,18]. The RS-LMTO-ASA is a linear method, and the solutions are accurate around a given energy E m , usually taken at the center of gravity of the occupied part of the s, p and d bands being considered.…”

Section: The Rs-lmto-asa Methodsmentioning

confidence: 99%

Orbital moments of 3d adatoms and Co nanostructures on Cu(001) surfaces

Klautau

Frota-Pessôa

2005

Surface Science

View full text Add to dashboard Cite

Section: The Rs-lmto-asa Methodsmentioning

confidence: 99%

Orbital moments of 3d adatoms and Co nanostructures on Cu(001) surfaces

Klautau

Frota-Pessôa

2005

Surface Science

View full text Add to dashboard Cite

“…The motivation for the choice of the Fe͞V systems is based on the strong influence of alloying on the magnetic moment (8), the relatively high structural quality of the obtained superlattices, and a wide range of ordering temperatures (9-15). Several theoretical studies for these systems exists, where large discrepancies are apparent between the theoretical and the experimental results concerning the magnetic moment, critical temperatures, and periods and strengths of the interlayer exchange coupling (8,(16)(17)(18)). This observation is by no means unique for Fe͞V systems but is found for almost all multilayer systems.…”

mentioning

confidence: 99%

On the sharpness of the interfaces in metallic multilayers

Holmström

Nordström

Bergqvist

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We show that the three most relevant magnetic properties (magnetic moment, critical temperature, and interlayer exchange coupling) of metallic multilayers can be reproduced with good accuracy by first principles theory, provided that the picture of atomically sharp interfaces is abandoned and one allows instead for both interface alloying and interface roughness. The interface of a metallic multilayer (exemplified by the Fe͞V system) is demonstrated to, at best, have interdiffusion essentially over two to three atomic layers on each side of the interface. Our conclusions are the result of combining experimental work with theoretical modeling, and we argue that this approach is the best avenue to obtain accurate information about the interface quality of metallic multilayers.T he study of physical properties of multilayers (structural, elastic, magnetic, and transport) is one of the most prosperous and rich branches of materials science today (1-3). By growing different atomic layers on top of each other, new phenomena have been observed, e.g., a reduced critical temperature for magnetic ordering, an oscillating interlayer exchange coupling (4), and giant magneto resistance (5). There are several ways in which these properties are used in nanotechnology, using for instance the giant magneto resistance effect (4, 5) in data storage and computer memories. Single-crystal multilayers represent the highest obtainable degree of perfection, with respect to interface and crystalline quality. This type of multilayer is often referred to as a superlattice.Typically, superlattices are grown by molecular beam epitaxy or sputtering. The growth temperature has to be sufficiently high to ensure large surface mobility and thereby enable layer-bylayer growth (6). At the same time, the temperature must be sufficiently low to prevent the metals from interdiffusing and thereby forming alloys. This delicate balance between surface and bulk mobility is of uttermost importance because, as we shall see, all properties that are special for multilayers (interlayer exchange coupling, magnetic moments, and critical temperatures) depend on the interface quality. Although it has been difficult to assess the interface quality in multilayers, it is safe to conclude that an ideal layer-by-layer growth is never obtained.In magnetic superlattices, interface roughness and interface mixing (7) are the most important types of imperfections. These types are schematically illustrated in Fig. 1. In the figure we specify the geometrical extent of the roughness and mixing via the parameters ⌫ T and ⌫ C , respectively. The mixing is assumed to follow a normal distribution with a width specified by ⌫ C . For the roughness we assume that it is composed of terraces with large lateral extent, such that a multilayer of formal composition, e.g., Fe 3 V 7 , may be thought to be composed of multilayers Fe 2 V 8 , Fe 3 V 7 , and Fe 4 V 6 , with a distribution specified by ⌫ T . For details of how the structure of the interface was constructed mathematically, please...

show abstract

“…The magnetic contribution arising from the V interfaces reduces the obtained magnetization, as the interface regions of V are antiferromagnetically aligned to the Fe layers. 1,20,[31][32][33][34][35] The resulting average magnetic moment per Fe atom ͑ Fe eq ͒ for the NG sample at 10 K is Fe eq Ϸ 0.7 B , as compared to the bulk value Fe Ϸ 2.2 B . This is in agreement with other established results.…”

Section: A Squid Measurementsmentioning

confidence: 99%

Influence of the distribution of the inherent ordering temperature on the ordering in layered magnets

et al. 2009

View full text Add to dashboard Cite

We study the influence of gradients in the inherent ordering temperature of coupled layered magnets on the overall magnetic ordering. The gradients were accomplished by growing Fe͑001͒ layers with thicknesses ranging from two to three monolayers, all separated by seven monolayers of V͑001͒. Two types of gradient superstructures were grown: one with the highest and one with the lowest inherent ordering temperature in the center of the samples. The superstructure with the thinnest outermost Fe layers exhibits lower ordering temperature, demonstrating the importance of the sequence of the layers. Both these structures order at temperatures significantly lower than a superlattice with a constant thickness of the Fe layers ͑three monolayers͒. The results highlight the intricate collective aspects of the magnetic ordering in layered magnets, which are not captured by current models in magnetism research.

show abstract

Magnetism of Fe/V and Fe/Co multilayers

Cited by 31 publications

References 42 publications

Orbital moments of 3d adatoms and Co nanostructures on Cu(001) surfaces

Orbital moments of 3d adatoms and Co nanostructures on Cu(001) surfaces

On the sharpness of the interfaces in metallic multilayers

Influence of the distribution of the inherent ordering temperature on the ordering in layered magnets

Contact Info

Product

Resources

About