Magnetic characteristics and frequency dependence of permeability in Fe–B–N thin films

Abstract

Magnetic characteristics and the frequency dependence of permeability for Fe-B-N thin films have been studied. Among the compositions investigated, Fe 94.9 B 1.3 N 3.8 exhibited excellent soft-magnetic properties: High saturation induction, B sϳ 20.6 kG, and low coercivity, H cϳ 0.1 Oe. An anomalous change of the incremental permeability ratio ͑PR͒ curve as a function of external magnetic field for the films measured above 4 MHz was observed, indicating a considerable variation in the magnetic softness in the high-frequency region. The changes of PR in low external fields seem to be useful for the evaluation of the magnetic softness in thin-film-type materials.

Novel nanostructure and magnetic properties of Co–Fe–Hf–O films

“…For these applications, magnetic thin films are required to have high electrical resistivity (ρ) to minimize energy loss due to eddy currents, and a large saturation magnetization (4π M s ) and hard-axis anisotropy field (H kH ) to increase the magnetic switching capacity at high frequencies [7,10]. Although sputtered metallic films have long been used in magnetic storage applications, owing to their good high-density response and high saturation magnetization that enable the fast switching of high coercivity media, these materials are not desirable for use in devices working in the gigahertz regime [1][2][3][4][5]. This is because their electrical resistivity is relatively low, resulting in large energy losses due to eddy currents; in particular such a good high-frequency magnetic response cannot be achieved in the GHz-frequency range [3][4][5].…”

“…One of the key ingredients in the study of these material systems is understanding the correlation between their chemistry, structure and magnetic properties in order to design and produce novel thin films which meet the specific requirements of modern technologies [1,7]. Therefore, considerable efforts have been devoted to clarifying the mechanism of film growth, the origin of magnetic couplings, spin transport across interfaces and spin-lattice interactions in magnetic thin films and nanostructures [2][3][4][5][6][7][8][9]. 4 Author to whom any correspondence should be addressed.…”

“…Magnetic thin films are being widely used for a large number of technological applications, such as sensors and media for magnetic recording, automotive and aerospace industries, and are one of the most important tools for the preparation of multifunctional materials [1][2][3][4][5][6][7]. One of the key ingredients in the study of these material systems is understanding the correlation between their chemistry, structure and magnetic properties in order to design and produce novel thin films which meet the specific requirements of modern technologies [1,7].…”

“…Although sputtered metallic films have long been used in magnetic storage applications, owing to their good high-density response and high saturation magnetization that enable the fast switching of high coercivity media, these materials are not desirable for use in devices working in the gigahertz regime [1][2][3][4][5]. This is because their electrical resistivity is relatively low, resulting in large energy losses due to eddy currents; in particular such a good high-frequency magnetic response cannot be achieved in the GHz-frequency range [3][4][5].…”