The magnetic and structural properties in Co/Cu/Co sandwiches with Ni and Cr buffer layers were investigated. It was found that the coercivity in Ni layer buffered samples decreases with increasing Ni layer thickness,...The magnetic and structural properties in Co/Cu/Co sandwiches with Ni and Cr buffer layers were investigated. It was found that the coercivity in Ni layer buffered samples decreases with increasing Ni layer thickness, while that in Cr layer buffered ones increases with increasing Cr layer thickness, leading to a large difference in field sensitivity of their giant magnetoresistance (GMR) properties. X-ray diffraction and high resolution transmission electron microscope images exhibited that there is a strong fcc (111) texture in the samples with Ni buffer layer. But there are only randomly oriented potycrystalline grains in Cr buffered sandwiches. According to atomic force microscope topography, the surface roughness of Cr buffered sandwiches is smaller than that of Ni buffered ones. It is demonstrated that buffer layer influences both magnetic and structural properties in Co/Cu/Co sandwiches as well as their GMR characteristics.展开更多
The effects of Ni buffer layer on the giant magnetoresistance structure of Co/Cu/Co sandwich are investigated systematically in this paper.It is found that Ni buffer layer can induce the crystallization of the lower N...The effects of Ni buffer layer on the giant magnetoresistance structure of Co/Cu/Co sandwich are investigated systematically in this paper.It is found that Ni buffer layer can induce the crystallization of the lower Ni/Co layer and produce small coercivity,thus enlarging the difference in the magnetic behavior between the two magnetic layers in the sandwich.Moreover,the use of the Ni buffer layer can also improve the interface flatness in the sandwich.All these factors enhance the sensitivity of the Ni buffered sandwich.展开更多
Highly cube textured Ni tapes are produced by heavy cold rolling and recrystallization annealing. The textured nickel tapes have been proven to be suitable substrates for YBCO superconducting tape. Nevertheless, rolli...Highly cube textured Ni tapes are produced by heavy cold rolling and recrystallization annealing. The textured nickel tapes have been proven to be suitable substrates for YBCO superconducting tape. Nevertheless, rolling damage and grain boundary grooves on Ni influence the epitaxial growth of highly textured buffer and YBCO layers. The polishing of the Ni substrate surface may play a crucial role in making it beneficial to epitaxial film deposition. In our work, several polishing methods were adopted on Ni to reduce the depth of rolling damage and grain boundary grooves. On the polished Ni substrates, textured Y2O3 buffer layers were deposited using RF sputtering. XRD results show that in-plane texture of Y2O3 films will minish with the decreasing of the Ni substrate surface roughness. AFM results show that average grain size of the Y2O3 film is biggest and surface is coarse in film on flatter Ni surface.展开更多
The buffer layer CeO2 films were grown on cube textured metallic Ni substrates by using reactive magnetrun sputtering. Ar/H2 mixed atmosphere, which effectively inhibited the formation of NiO, was used as pre-depositi...The buffer layer CeO2 films were grown on cube textured metallic Ni substrates by using reactive magnetrun sputtering. Ar/H2 mixed atmosphere, which effectively inhibited the formation of NiO, was used as pre-depositing gas before CeO2 films were grown in Ar and 02. At 700 ℃ under the total pressure of 26 Pa,the pure c-axis orientation tilm was obtained. X-ray θ-2θscan, pole figure and φ-scan were used to observe the microstructure of the buffer layer. The resuits show that CeO2 film has strong cube texture and the FWHM is 9°. In addition, the CeO2 film is dense and crack-free.展开更多
The CeO2 and Y2O3 buffer layers were deposited on the cube textured metallic Ni substrates by using reactive magnetron sputtering. Ar/H2 mixed atmosphere, which is used as pre-depositing gas, can effectively inhibit t...The CeO2 and Y2O3 buffer layers were deposited on the cube textured metallic Ni substrates by using reactive magnetron sputtering. Ar/H2 mixed atmosphere, which is used as pre-depositing gas, can effectively inhibit the formation of NiO. In addition, the linear relationship between pre-depositing time and total depositing time is required to ensure the epitaxial growth of the films. The growth conditions of CeO2 and Y2O3 were comparatively studied, and it is found that the windows of substrate temperatures and pressures for CeO2 films are wider than that for Y2O3 films.展开更多
CeO2/YSZ/CeO2 buffer layers were deposited on biaxially textured Ni substrates by pulsed laser deposition. The influence of the processing parameters on the texture development of the seed layer CeO2 was investigated....CeO2/YSZ/CeO2 buffer layers were deposited on biaxially textured Ni substrates by pulsed laser deposition. The influence of the processing parameters on the texture development of the seed layer CeO2 was investigated. Epitaxial films of YBCO were then grown in situ on the CeO2/YSZ （yttria-stabilized ZrO2）/CeO2-buffered Ni substrates. The resulting YBCO conductors exhibited self-fleld critical current density Jc of more than 1 MA/cm^2 at 77K and superconducting transition temperature Tc of about 91K.展开更多
文摘The magnetic and structural properties in Co/Cu/Co sandwiches with Ni and Cr buffer layers were investigated. It was found that the coercivity in Ni layer buffered samples decreases with increasing Ni layer thickness, while that in Cr layer buffered ones increases with increasing Cr layer thickness, leading to a large difference in field sensitivity of their giant magnetoresistance (GMR) properties. X-ray diffraction and high resolution transmission electron microscope images exhibited that there is a strong fcc (111) texture in the samples with Ni buffer layer. But there are only randomly oriented potycrystalline grains in Cr buffered sandwiches. According to atomic force microscope topography, the surface roughness of Cr buffered sandwiches is smaller than that of Ni buffered ones. It is demonstrated that buffer layer influences both magnetic and structural properties in Co/Cu/Co sandwiches as well as their GMR characteristics.
基金This work was supported by the Shanghai Research Center for Applied Physics and Shanghai Research (99JC14003) and Development Foundation for Application Materials (No. 98006).
文摘The effects of Ni buffer layer on the giant magnetoresistance structure of Co/Cu/Co sandwich are investigated systematically in this paper.It is found that Ni buffer layer can induce the crystallization of the lower Ni/Co layer and produce small coercivity,thus enlarging the difference in the magnetic behavior between the two magnetic layers in the sandwich.Moreover,the use of the Ni buffer layer can also improve the interface flatness in the sandwich.All these factors enhance the sensitivity of the Ni buffered sandwich.
文摘Highly cube textured Ni tapes are produced by heavy cold rolling and recrystallization annealing. The textured nickel tapes have been proven to be suitable substrates for YBCO superconducting tape. Nevertheless, rolling damage and grain boundary grooves on Ni influence the epitaxial growth of highly textured buffer and YBCO layers. The polishing of the Ni substrate surface may play a crucial role in making it beneficial to epitaxial film deposition. In our work, several polishing methods were adopted on Ni to reduce the depth of rolling damage and grain boundary grooves. On the polished Ni substrates, textured Y2O3 buffer layers were deposited using RF sputtering. XRD results show that in-plane texture of Y2O3 films will minish with the decreasing of the Ni substrate surface roughness. AFM results show that average grain size of the Y2O3 film is biggest and surface is coarse in film on flatter Ni surface.
文摘The buffer layer CeO2 films were grown on cube textured metallic Ni substrates by using reactive magnetrun sputtering. Ar/H2 mixed atmosphere, which effectively inhibited the formation of NiO, was used as pre-depositing gas before CeO2 films were grown in Ar and 02. At 700 ℃ under the total pressure of 26 Pa,the pure c-axis orientation tilm was obtained. X-ray θ-2θscan, pole figure and φ-scan were used to observe the microstructure of the buffer layer. The resuits show that CeO2 film has strong cube texture and the FWHM is 9°. In addition, the CeO2 film is dense and crack-free.
基金The National Natural Science Foundation of China(No.11404291)the Aeronautical Science Foundation(Nos.2014ZF55013,2015ZF55013)+1 种基金the Outstanding Person Foundation of Henan Province(No.164200510006)the Key Research Project of the Education Department Henan Province(No.15A140042)
文摘The CeO2 and Y2O3 buffer layers were deposited on the cube textured metallic Ni substrates by using reactive magnetron sputtering. Ar/H2 mixed atmosphere, which is used as pre-depositing gas, can effectively inhibit the formation of NiO. In addition, the linear relationship between pre-depositing time and total depositing time is required to ensure the epitaxial growth of the films. The growth conditions of CeO2 and Y2O3 were comparatively studied, and it is found that the windows of substrate temperatures and pressures for CeO2 films are wider than that for Y2O3 films.
文摘CeO2/YSZ/CeO2 buffer layers were deposited on biaxially textured Ni substrates by pulsed laser deposition. The influence of the processing parameters on the texture development of the seed layer CeO2 was investigated. Epitaxial films of YBCO were then grown in situ on the CeO2/YSZ （yttria-stabilized ZrO2）/CeO2-buffered Ni substrates. The resulting YBCO conductors exhibited self-fleld critical current density Jc of more than 1 MA/cm^2 at 77K and superconducting transition temperature Tc of about 91K.
