Ru/FeCoB double layered film with high in-plane magnetic anisotropy field of 500 Oe

Abstract

An algorithm to extract effective magnetic parameters of thin film with in-plane uniaxial magnetic anisotropy J. Appl. Phys. 107, 09C507 (2010); 10.1063/1.3357325 Direct observation of an anisotropic in-plane residual stress induced by B addition as an origin of high magnetic anisotropy field of Ru/FeCoB film J. Appl. Phys. 107, 09A323 (2010); 10.1063/1.3350899Ru/FeCoB crystalline soft magnetic underlayers with high anisotropy field for CoPtCr -SiO 2 granular perpendicular magnetic recording media FeCoB layers prepared on Ru underlayer possess a high saturation magnetization M s and a high in-plane magnetic anisotropy filed H k . Effects of preparation conditions were investigated. Low Ar gas pressure condition and thicker film thickness were effective to attain distortion of FeCo crystallite. As the crystallinity of Ru underlayer became higher, higher H k was induced. The accumulation of anisotropic stress in the film caused by the oblique incidences of depositing atoms with high energy seems to be one of the important effects to attain high anisotropy field. It was succeeded to prepare the Ru/FeCoB film with high H k of 500 Oe.

Tunable zero-field ferromagnetic resonance frequency from S to X band in oblique deposited CoFeB thin films

“…Thus, large 4π M s is necessary for both higher permeability and higher resonance frequency. CoFe alloy, which is one of the magnetic materials with largest saturation magnetization, is widely investigated in magnetic thin films 20 21 22 23 , Among these works, the Ru/FeCoB double layered film also indicates that large anisotropy can be induced in FeCoB layer 24 , In FeCoB thin films, the element B was selected as dopant to reduce the magneto-crystalline anisotropy, then, the in-plane uniaxial anisotropy of the films can be induced more easily 25 , In this work, we choose Co 69.0 Fe 27.8 B 3.2 (CFB) as the composition of the magnetic thin films, and combine with the oblique deposition technique to obtain such magnetic thin films with not only ultra-high resonance frequency but also tunable resonance frequency in an ultra-large range.…”

Ultra-high resistive and anisotropic CoPd–CaF2 nanogranular soft magnetic films prepared by tandem-sputtering deposition

“…However, inverse magnetostriction effect can be ignored because the magnetic easy axis is obedient to induction field in sample preparation, and annealing usually relaxes the residual internal stress. Furthermore, no anisotropic lattice strain [35,36] was found from the XRD, and the magnetostriction constant of alloys is attenuated by introducing matrix material [27]. Thus, the authors are now suggesting the possibility that the anisotropy of the granular films may not be explained only by a simple random anisotropy model for nanocrystalline soft magnetic materials [13].…”

“…Some pioneer materials exhibit higher f r than our film owing to their much higher M s or H k [36,46]. However, we believe that our films are the most suitable material for GHz devices at present.…”

Permeability Measurements of Magnetic Thin Film with Microstrip Probe

“…The specif ed permeability in the width direction corresponds to the high frequency impedance, while sacrif cing applied magnetic f eld uniformity. In this paper, CoFeB f lm 6) and FeCoB/Ru film 7) with a large anisotropy f eld were evaluated as a demonstration of broadband evaluation. arranged around the bias coil to increase the dc magnetic field.…”