Shape-independent permeability model for uniaxially-anisotropic ferromagnetic thin films

Jamieson, Brice; O’Donnell, Terence; Kulkarni, Santosh; Roy, Saibal

doi:10.1063/1.3430061

Cited by 15 publications

(5 citation statements)

References 12 publications

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“…By comparing the lowest energies in the three directions, we can find out which of these directions are the ground-state orientation of the domains. 29,30,39 The simulation parameters are given in Table S2.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

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Influence of the Aspect Ratio of Iron Oxide Nanorods on Hysteresis-Loss-Mediated Magnetic Hyperthermia

Sugumaran

Yang

Wang

et al. 2021

ACS Appl. Bio Mater.

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Owing to the problems associated with conventional cancer treatment methods, magnetic hyperthermia-based cancer therapy has gained importance recently. Achieving the desired heating effect at the site of the tumor with a minimal concentration of iron oxide nanoparticles (IONPs) and a safer field is necessary to explore the advantages of hyperthermia. For one to address this challenge, biocompatible IONPs with a desirable magnetic response at a tolerable field are necessary. In this work, magnetic shape anisotropy of iron oxide nanorods (NR) of different lengths (70, 115, 170, and 210 nm) with different aspect ratios ranging from 1.55 to 3.2 was explored to achieve higher hysteresis loss, in turn leading to better hyperthermia efficiency. The magnetic properties of the NRs with respect to the applied field were studied using micromagnetic simulation. Even though the nanorods with high aspect ratio showed a higher hysteresis loss of 69485 J/m3 at 2000 Oe, the field required to attain it was high and well beyond the safety limit. From nanorods of various aspect ratios, the nanorod with a lower aspect ratio of 1.55 and a length of 70 nm exhibited a better hysteresis loss and specific absorption rate (SAR) value of 4214 W g–1 was achieved at a frequency and alternating magnetic field of 400 kHz and 800 Oe, respectively. The PEGylated GO-Nanorod of 70 nm exhibited excellent antitumor efficacy in 4T1 tumor model mice by obstructing the tumor progression within a safer dosage and field.

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Section: ■ Materials and Methodsmentioning

confidence: 99%

“…This is done in LLG Micromagnetics in three different directions: in-plane, out-of-plane, and vortex. By comparing the lowest energies in the three directions, we can find out which of these directions are the ground-state orientation of the domains. ,, The simulation parameters are given in Table S2.…”

Section: Methodsmentioning

confidence: 99%

Influence of the Aspect Ratio of Iron Oxide Nanorods on Hysteresis-Loss-Mediated Magnetic Hyperthermia

Sugumaran

Yang

Wang

et al. 2021

ACS Appl. Bio Mater.

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“…However, the relative permeability (μ) of the core material does change with the shape and aspect ratio of the core material. The impact of different core shapes on the permeability has been clearly explained in previous reports [17]. The shape anisotropy is a key anisotropy energy which influences the magnetic properties in the soft magnetic thin films in particular the overall material anisotropy field and relative permeability in turn.…”

Section: Assembly and Characterization Of Pcb Thin Film Inductorsmentioning

confidence: 97%

PCB Embedded Bondwire Inductors With Discrete Thin-Film Magnetic Core for Power Supply in Package

Kulkarni

Jordan

et al. 2018

IEEE J. Emerg. Sel. Topics Power Electron.

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“…An appropriate material for the magnetic core of a power transformer should have a high saturation magnetization, high permeability, high resistivity, low coercivity and high thermal conductivity. Among the above-mentioned properties, resistivity, thermal conductivity and saturation magnetization are intrinsic properties of a material, while the other depend on the external effects, such as the shape and dimension of the core [19], fabrication process [20], operating frequency [10], extra annealing [20], and excitation waveform [21]. All these parameters need to be considered when designing an efficient core.…”

Section: Magnetic Materials For Power Conversion Applicationsmentioning

confidence: 99%

3-D Microtransformers for DC–DC On-Chip Power Conversion

Moazenzadeh

Sandoval

Spengler

et al. 2015

IEEE Trans. Power Electron.

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We address the miniaturization of power converters by introducing novel, 3D microtransformers with magnetic core for low-MHz frequency applications. The core is fabricated by lamination and microstructuring of Metglas ® 2714A magnetic alloy. The solenoids of the microtransformers are wound around the core using a ball-wedge wirebonder. The wirebonding process is fast, allowing the fabrication of solenoids with up to 40 turns in 10 s. The fabricated devices yield the high inductance per unit volume of 2.95 µH/mm 3 and energy per unit volume of 133 nJ/mm 3 at the frequency of 1 MHz. The power efficiency of 64-76% are measured for different turns ratio with coupling factors as high as 98%.To demonstrate the applicability of our passive components two PWM controllers were selected to implement an isolated and a nonisolated switch mode power supply. The isolated converter operates with overall efficiency of 55% and maximum output power of 136 mW, then we experimentally demonstrate how we increased this efficiency to 71% and output power to 408 mW. The non-isolated converter can deliver an overall efficiency of 81% with a maximum output power of 515 mW. Finally, we benchmarked the results to underline the potential of the technology for power on-chip applications.Index Terms-Transformer, Magnetic layered film, DC-DC power conversion, Micromachining.

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Shape-independent permeability model for uniaxially-anisotropic ferromagnetic thin films

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Cited by 15 publications

References 12 publications

Influence of the Aspect Ratio of Iron Oxide Nanorods on Hysteresis-Loss-Mediated Magnetic Hyperthermia

Influence of the Aspect Ratio of Iron Oxide Nanorods on Hysteresis-Loss-Mediated Magnetic Hyperthermia

PCB Embedded Bondwire Inductors With Discrete Thin-Film Magnetic Core for Power Supply in Package

3-D Microtransformers for DC–DC On-Chip Power Conversion

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