title: Recipe for High Moment Materials with Rare-earth and 3d Transition Metal Composites.
abstract: Materials with high volume magnetization are perpetually needed for the generation of sufficiently large magnetic fields by writer pole of magnetic hard disks, especially for achieving increased areal density in storage media. In search of suitable materials combinations for this purpose, we have employed density functional theory to predict the magnetic coupling between iron and gadolinium layers separated by one to several monolayers of 3d transition metals (Sc-Zn). We demonstrate that it is possible to find ferromagnetic coupling for many of them and in particular for the early transition metals giving rise to high moment. Cr and Mn are the only elements able to produce a significant ferromagnetic coupling for thicker spacer layers. We also present experimental results on two trilayer systems Fe/Sc/Gd and Fe/Mn/Gd. From the experiments, we confirm a ferromagnetic coupling between Fe and Gd across a 3 monolayers Sc spacer or a Mn spacer thicker than 1 monolayer. In addition, we observe a peculiar dependence of Fe/Gd magnetic coupling on the Mn spacer thickness.
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala, Sweden.
authors.forename: Carmine
authors.initials: C
authors.lastname: Autieri
authors.affiliation: Faculty of Physics Duisburg-Essen (CeNIDE), University of Duisburg-Essen, D-47057 Duisburg, Germany.
authors.forename: P Anil
authors.initials: PA
authors.lastname: Kumar
authors.affiliation: Faculty of Physics Duisburg-Essen (CeNIDE), University of Duisburg-Essen, D-47057 Duisburg, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Walecki
authors.affiliation: Faculty of Physics Duisburg-Essen (CeNIDE), University of Duisburg-Essen, D-47057 Duisburg, Germany.
authors.forename: Samira
authors.initials: S
authors.lastname: Webers
authors.affiliation: Seagate Technology, 1 Disc Drive, Springtown, Northern Ireland BT48 0BF, United Kingdom.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Gubbins
authors.affiliation: Faculty of Physics Duisburg-Essen (CeNIDE), University of Duisburg-Essen, D-47057 Duisburg, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Wende
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala, Sweden.
authors.forename: Biplab
authors.initials: B
authors.lastname: Sanyal