High annealing tolerance and the microstructure study in perpendicular magnetized MgO/CoFeB/MgO structures with thin W spacer layer

Wang, Shuanghai; Li, Minghua; Zhang, Shijie; Fang, Shuai; Wang, Dongwei; Yu, Guo

doi:10.1016/j.jmmm.2019.02.023

Cited by 3 publications

(3 citation statements)

References 22 publications

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“…Due to its excellent characteristics, the Co-Fe system has received extensive attention. At present, Co-Fe alloys are often used in magnetic devices, sensors, actuators, and magnetic storage [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Magnetic properties are affected by thickness, crystallinity, and interfacial interactions.…”

Section: Introductionmentioning

confidence: 99%

Effects of Annealing and Thickness of Co60Fe20Yb20 Nanofilms on Their Structure, Magnetic Properties, Electrical Efficiency, and Nanomechanical Characteristics

et al. 2022

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X-ray diffraction (XRD) analysis showed that metal oxide peaks appear at 2θ = 47.7°, 54.5°, and 56.3°, corresponding to Yb2O3 (440), Co2O3 (422), and Co2O3 (511). It was found that oxide formation plays an important role in magnetic, electrical, and surface energy. For magnetic and electrical measurements, the highest alternating current magnetic susceptibility (χac) and the lowest resistivity (×10−2 Ω·cm) were 0.213 and 0.42, respectively, and at 50 nm, it annealed at 300 °C due to weak oxide formation. For mechanical measurement, the highest value of hardness was 15.93 GPa at 200 °C in a 50 nm thick film. When the thickness increased from 10 to 50 nm, the hardness and Young’s modulus of the Co60Fe20Yb20 film also showed a saturation trend. After annealing at 300 °C, Co60Fe20Yb20 films of 40 nm thickness showed the highest surface energy. Higher surface energy indicated stronger adhesion, allowing for the formation of multilayer thin films. The optimal condition was found to be 50 nm with annealing at 300 °C due to high χac, strong adhesion, high nano-mechanical properties, and low resistivity.

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Section: Introductionmentioning

confidence: 99%

Effects of Annealing and Thickness of Co60Fe20Yb20 Nanofilms on Their Structure, Magnetic Properties, Electrical Efficiency, and Nanomechanical Characteristics

et al. 2022

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“…Another way to enhance PMA properties is to use multilayer structures, but this method causes the multilayer films' whole thickness to increase. Transition metal (TM) alloys have a unique capability that can be used to improve some properties of magnetic films, including their thermal stability, mechanical strength, and chemical and physical properties [12][13][14][15][16][17][18]. Ghaferi et al used a citrate bath to test a CoFeW alloy.…”

Section: Introductionmentioning

confidence: 99%

Impact of Annealing on Magnetic Properties and Structure of Co40Fe40W20 Thin Films on Si(100) Substrate

et al. 2021

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Co40Fe40W20 monolayers of different thicknesses were deposited on Si(100) substrates by DC magnetron sputtering, with Co40Fe40W20 thicknesses from 10 to 50 nm. Co40Fe40W20 thin films were annealed at three conditions (as-deposited, 250 °C, and 350 °C) for 1 h. The structural and magnetic properties were then examined by X-ray diffraction (XRD), low-frequency alternative-current magnetic susceptibility (χac), and an alternating-gradient magnetometer (AGM). The XRD results showed that the CoFe (110) peak was located at 2θ = 44.6°, but the metal oxide peaks appeared at 2θ = 38.3, 47.6, 54.5, and 56.3°, corresponding to Fe2O3 (320), WO3 (002), Co2O3 (422), and Co2O3 (511), respectively. The saturation magnetization (Ms) was calculated from the slope of the magnetization (M) versus the CoFeW thickness. The Ms values calculated in this manner were 648, 876, 874, and 801 emu/cm3 at the as-deposited condition and post-annealing conditions at 250, 350, and 400 °C, respectively. The maximum MS was about 874 emu/cm3 at a thickness of 50 nm following annealing at 350 °C. It indicated that the MS and the χac values rose as the CoFeW thin films’ thickness increased. Owing to the thermal disturbance, the MS and χac values of CoFeW thin films after annealing at 350 °C were comparatively higher than at other annealing temperatures. More importantly, the Co40Fe40W20 films exhibited a good thermal stability. Therefore, replacing the magnetic layer with a CoFeW film improves thermal stability and is beneficial for electrode and strain gauge applications.

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“…The PMA in Ta/CoFeB/MgO stack, first identified by Ikeda et al, has promising applications in spin-transfer torque devices [3]. Moreover, magnetic tunnel junctions (MTJs) have been widely investigated because of their wide applications in spintronic magnetic devices, such as reading heads of hard disks and magnetoresistance random access memories (MRAM) [4][5][6][7]. The CoFeB film was combined with the MgO layer to form MTJs.…”

Section: Introductionmentioning

confidence: 99%

Annealing Effect on the Contact Angle, Surface Energy, Electric Property, and Nanomechanical Characteristics of Co40Fe40W20 Thin Films

et al. 2021

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This study investigated Co40Fe40W20 single-layer thin films according to their corresponding structure, grain size, contact angle, and surface energy characteristics. Co40Fe40W20 alloy thin films of different thicknesses, ranging from 10 to 50 nm, were sputtered on Si(100) substrates by DC magnetron sputtering. The thin films were annealed under three conditions: as-deposited, 250 °C, and 350 °C temperatures, respectively. The Scherrer equation was applied to calculate the grain size of Co40Fe40W20 thin films. The results show that the grain size of CoFe(110) increased simultaneously with the increase of post-annealing temperature, suggesting that the crystallinity of Co40Fe40W20 thin films increased with the post-annealing temperature. Moreover, the contact angles of all Co40Fe40W20 thin films were all less than 90°, suggesting that Co40Fe40W20 thin films show changes in the direction of higher hydrophilicity. However, we found that their contact angles decreased as the grain size of CoFe increased. Finally, the Young equation was applied to calculate the surface energy of Co40Fe40W20 thin films. After post-annealing, the surface energy of Co40Fe40W20 thin films increased with the rising post-annealing temperature. This is the highest value of surface energy observed for 350 °C. In addition, the surface energy increased as the contact angle of Co40Fe40W20 thin films decreased. The high surface energy means stronger adhesion, allowing the formation of multilayer thin films with magnetic tunneling junctions (MTJs). The sheet resistance of the as-deposited and thinner CoFeW films is larger than annealed and thicker CoFeW films. When the thickness is from 10 nm to 50 nm, the hardness and Young’s modulus of the CoFeW film also show a saturation trend.

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High annealing tolerance and the microstructure study in perpendicular magnetized MgO/CoFeB/MgO structures with thin W spacer layer

Cited by 3 publications

References 22 publications

Effects of Annealing and Thickness of Co60Fe20Yb20 Nanofilms on Their Structure, Magnetic Properties, Electrical Efficiency, and Nanomechanical Characteristics

Effects of Annealing and Thickness of Co60Fe20Yb20 Nanofilms on Their Structure, Magnetic Properties, Electrical Efficiency, and Nanomechanical Characteristics

Impact of Annealing on Magnetic Properties and Structure of Co40Fe40W20 Thin Films on Si(100) Substrate

Annealing Effect on the Contact Angle, Surface Energy, Electric Property, and Nanomechanical Characteristics of Co40Fe40W20 Thin Films

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