Effect of grain size on magnetic and nanomechanical properties of Co60Fe20B20 thin films

Chen, Yuan-Tsung; Chang, Chia‐Chi

doi:10.1016/j.jallcom.2010.03.141

Cited by 38 publications

(15 citation statements)

References 24 publications

(24 reference statements)

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“…However, they do not possess low coercivity values and therefore researchers have employed different methods in order to reduce their coercivity [7][8][9]. Recent advances in the area of nanocrystalline materials have shown that grain size reduction in ferromagnetic materials can result in very significant reduction in coercivity value of thin films with no effect on their saturation magnetization [9,10]. The other approach, used by many investigators, is addition of elements such as Ni, Zn, N, into Co-Fe system [11][12][13][14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Studies of electrical resistivity and magnetic properties of nanocrystalline CoFeCu thin films electrodeposited from citrate-added baths

Mehrizi

Sohi

Shafahian

et al. 2011

J Mater Sci: Mater Electron

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In this study, nanocrystalline CoFeCu thin films were electrodeposited at different current densities from baths with natural pH (around 5.2) and containing 20 g/L citrate sodium. The relationship of films structure with soft magnetic properties and electrical resistivity, which are required for new generation magnetic head core, were investigated. SEM, EDS, XRD, TEM, VSM and four probe-point methods were used for characterization of the deposited films. The deposited films exhibited very uniform and homogenous structure with co-axis grains (confirmed by (111) and (110) poles figures and TEM images) throughout the coating. Overall, it was noticed that increasing current density from 1 to 24 mA/cm 2 reduced both grain size (from 63 to 8 nm) and coercivity (from 20 to 1 Oe) of the films. In addition, plotting Log (Hc) versus Log (D 6 ) demonstrated that the coercivity of the films followed ''D 6 law''. Moreover, increasing current density changed phase structures of the films from FCC (Cu)?FCC (Co) to FCC (Co) and then to FCC (Co)

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Section: Introductionmentioning

confidence: 99%

Studies of electrical resistivity and magnetic properties of nanocrystalline CoFeCu thin films electrodeposited from citrate-added baths

Mehrizi

Sohi

Shafahian

et al. 2011

J Mater Sci: Mater Electron

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“…In the case of CoFeB we use a combined supercell plus VCA approach. In view of the residual [110] texture that has been found for CoFeB films [14], a possible contribution to the transverse resistivity by anisotropic Berry-phase AHE is also examined [15]. However, in our measurements it is found to be negligible.…”

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confidence: 73%

“…Since a residual [110] texture has been found in CoFeB films [14] that can give rise to a magnetization component perpendicular to the film, we also examine the possibility that the transverse signals shown in Figs. 1 and 2 may partly be governed by the anomalous Hall effect [26].…”

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confidence: 99%

Origin of the Planar Hall Effect in NanocrystallineCo60Fe20B20

et al. 2011

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An angle dependent analysis of the planar Hall effect (PHE) in nanocrystalline single-domain Co 60 Fe 20 B 20 thin films is reported. In a combined experimental and theoretical study we show that the transverse resistivity of the PHE is entirely driven by anisotropic magnetoresistance (AMR). Our results for Co 60 Fe 20 B 20 obtained from first principles theory in conjunction with a Boltzmann transport model take into account the nanocrystallinity and the presence of 20 at. % boron. The ab initio AMR ratio of 0.12% agrees well with the experimental value of 0.22%. Furthermore, we experimentally demonstrate that the anomalous Hall effect contributes negligibly in the present case. DOI: 10.1103/PhysRevLett.107.086603 PACS numbers: 72.25.Ba, 71.70.Ej, 72.15.Gd Electron transport effects employing the electronic spin degree of freedom lie at the heart of spintronics and its applications not only in information technology [1] but more increasingly also in sensorics for biomedical purposes, where the utmost sensitivity for detecting minute magnetic stray fields is needed. The planar Hall effect (PHE) and the anomalous Hall effect (AHE) as well as tunneling magnetoresistance are promising phenomena for realizing highly sensitive sensors. From a materials point of view, nanocrystalline Co 60 Fe 20 B 20 (CoFeB) attracts growing attention since it combines large saturation magnetization with low coercivity [2,3], both favoring high sensitivities.PHE and AHE are both observed as a voltage transverse to the applied current [4,5] in contrast to the anisotropic magnetoresistance (AMR), which is measured in the longitudinal geometry. For PHE the magnetization M lies in the plane spanned by the current density j ¼ je x and the direction e y of the transverse voltage measurement, and for AHE the component of M perpendicular to j and e y matters. Although AMR has been known since Thomson's-later known as Lord Kelvin-observations in 1856 [6], PHE was discovered only a century later in polycrystalline permalloy [7]. More recently, PHE has also been found in crystalline La 2=3 Fe 1=3 MnO 3 [8] and as a very large effect at low temperatures in the dilute magnetic semiconductor (Ga,Mn)As [9]. The transverse resistance xy characterizing the PHE and the longitudinal resistivity xx denoting the AMR are given by [10] xy ¼ ð k À ? Þ sinÈ cosÈwhere k ( ? ) is the resistivity along (perpendicular to) the direction of the in-plane component of M, and È is the angle enclosed by j and M. A transverse voltage arises whenever the current is neither perpendicular nor parallel to the magnetization. Even though the AMR is a subtle spin-orbit effect, quantitatively reliable predictions from first principles based on the density functional theory (DFT) can be made [11,12]. In this Letter, we elucidate the role of AMR in the PHE in nanocrystalline Co 60 Fe 20 B 20 thin films experimentally and by ab initio calculations. We measure AMR and PHE in longitudinal and transverse four-probe transport experiments. The single-domain behavior enforced by an ...

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“…This formula can be utilized to calculate the grain size and determine the crystallinity [16,19]. As presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

Effect of grain size on magnetic and nanomechanical properties of Co60Fe20B20 thin films

Cited by 38 publications

References 24 publications

Studies of electrical resistivity and magnetic properties of nanocrystalline CoFeCu thin films electrodeposited from citrate-added baths

Studies of electrical resistivity and magnetic properties of nanocrystalline CoFeCu thin films electrodeposited from citrate-added baths

Origin of the Planar Hall Effect in NanocrystallineCo60Fe20B20

Effect of tunneling barrier as spacer on exchange coupling of CoFeB/AlOx/Co trilayer structures

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