Precessional dynamics of Ni45Fe55 thin films for ultrahigh frequency integrated magnetics

Abstract

Access to the full text of the published version may require a subscription. Future monolithic point of load switched mode power supplies will be expected to meet the energy requirements of miniaturized, high functionality electronic devices. Recently, Ni 45 Fe 55 has emerged as a potentially important material choice for use as a soft magnetic core material within high frequency integrated passive magnetic components. The operating frequency range of the integrated passives which form a key part of the point of load power supply must increase to allow for inductor/transformer miniaturization to become monolithic with power integrated circuits. In this work, an analysis of the high frequency permeability spectra of an electroplated Ni 45 Fe 55 thin film has been carried out to quantitatively analyze the material's high frequency performance. Complex permeability spectra of the film have been investigated at frequencies up to 9 GHz to identify both the film's spectroscopic splitting factor ͑g͒ and its effective dimensionless damping parameter ͑␣͒. The Kittel equation is utilized to identify g as 2.128, while ␣ is determined to be approximately 0.045. The critically damped condition for the film is also examined to extract ␣ in the critically damped case under a range of externally applied bias fields. It is concluded that for monolithic power inductors, improved device performance can be achieved when the ferromagnetic core is in an underdamped state up to a critical frequency. Rights

High-frequency Magnetic Properties of [Fe80Ni20-O/SiO2]n Multilayer Film Served as Magnetic Core of Solenoid Inductor

“…When operating at high frequency range, the eddy current loss in the magnetic core cannot be ignored. Therefore, the decrease of inductance was caused by the deterioration of the magnetic core performance near FMR [10].…”

“…The present predicament was that the high-frequency performance of integrated inductors with magnetic core was poor because of the serious eddy current loss, high-frequency magnetic loss, and ferromagnetic resonance loss near the FMR frequency of the conventional magnetic core materials with very lower resonance frequencies (f r ) [9]. Therefore, the high-frequency soft magnetic materials were the key requirements for realizing large-scale integrated circuit technology [10]. The lower f r of conventional magnetic materials limited the working frequency of the high frequency inductor components [11].…”

Substantially enhancing ferromagnetic resonance frequency via superposition of composition gradient sputtering and magnetoelectric coupling in FeCoAlO/PZN–PT heterostructures

“…The dominate microwave performance in MMICs is ferromagnetic resonance frequency f FMR , while the key approach to enhance f FMR is to increase the anisotropy magnetic field H K , as described by Kittel equation [7]. Many preparation methods were proposed to obtain a high H K , such as in-situ magnetic field deposition [8,9], post magnetic annealing, oblique sputtering [10,11], exchange coupling between ferromagnetic (FM) layer and antiferromagnetic (AFM) layer or FM layer with higher coercivity [12,13], and magnetoelectric (ME) coupling [14,15]. In our previous work [16][17][18][19], a novel composition gradient sputtering (CGS) method was applied to achieve a high uniaxial magnetic anisotropy in SMFs, which dramatically increased the in-plane uniaxial H K to 547 Oe due to the uniaxial stress distribution induced by composition gradient.…”

NiZn ferrite/Fe hybrid epoxy-based composites: extending magnetic properties to high frequency

“…Meanwhile, the ever-increasing demand for smaller, longer lasing, and novel design portable electronic devices has accelerated the development of multifunctional materials with low energy losses and high permeability for miniaturizing electronic components such as antennas, magnetic inductors [1], and current convertors [2][3][4]. Nowadays, many electronic devices operate in the very high frequency (30-300 MHz) range, such as television broadcasting, land-based mobile telephone stations and air traffic control communications, and therefore, materials with low energy losses and high permeability that are able to operate at these and higher frequencies are in high demand, both for conventional and possible metamaterial applications [5][6][7].…”