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1.
Effect of magnetic field annealing on microstructure and magnetic properties of FePt films 总被引:1,自引:0,他引:1
Y.B. Li L.R. Zhang J.M. Bai F.L Wei 《Journal of magnetism and magnetic materials》2010,322(23):3789-3791
FePt (20 nm) films were annealed in a magnetic field (along the normal direction of the films) at a temperature around the Curie temperature of L10 FePt. The influence of magnetic filed annealing on texture and magnetic properties of FePt films were investigated. The results indicate that preferential (0 0 1) orientation and perpendicular anisotropy can be obtained in L10 FePt films by using magnetic field annealing around the Curie temperature of L10 FePt. This is one of the potential methods to obtain (0 0 1) orientation and thus to improve the perpendicular anisotropy in FePt films. 相似文献
2.
用磁过滤脉冲真空电弧沉积方法制备了CoPt(FePt) C纳米复合薄膜,并在不同温度下进行了退火处理,研究了薄膜中碳的含量以及退火温度对薄膜结构与磁性能的影响.制备态薄膜经过足够高的温度退火后,x射线衍射和磁力显微镜分析发现,在碳基质中生成了面心四方相的CoPt(FePt)纳米颗粒.对于特定组分为Co24Pt31C45和Fe43Pt35C22的薄膜,矫顽力以及颗粒尺寸都随退火温度的升高而增大,当退火温度为700℃时,Co24Pt31C45薄膜的矫顽力为21×105A/m,晶粒尺寸为17nm;当退火温度为650℃时,Fe43Pt35C22相应值分别为28×105A/m和105nm.
关键词:
磁记录材料
磁性薄膜
CoPt
FePt纳米复合薄膜 相似文献
3.
S.C. Chen P.C. Kuo A.C. Sun C.Y. Chou Y.H. Fang T.H. Wu 《Journal of magnetism and magnetic materials》2006
An in-plane magnetic anisotropy of FePt film is obtained in the MgO 5 nm/FePt t nm/MgO 5 nm films (where t=5, 10 and 20 nm). Both the in-plane coercivity (Hc∥) and the perpendicular magnetic anisotropy of FePt films are increased when introducing an Ag-capped layer instead of MgO-capped layer. An in-plane coercivity is 3154 Oe for the MgO 5 nm/FePt 10 nm/MgO 5 nm film, and it can be increased to 4846 Oe as a 5 nm Ag-capped layer instead of MgO-capped layer. The transmission electron microscopy (TEM)-energy disperse spectrum (EDS) analysis shows that the Ag mainly distributed at the grain boundary of FePt, that leads the increase of the grain boundary energy, which will enhance coercivity and perpendicular magnetic anisotropy of FePt film. 相似文献
4.
K.K.M. Pandey N. GaurC.S. Bhatia 《Journal of magnetism and magnetic materials》2011,323(21):2658-2662
The microstructure and magnetic properties of FePt-C film deposited on the MgO/CrRu underlayer are studied in lieu of carbon doping in FePt and RF biasing assisted etching of the MgO underlayer. Increasing amounts of carbon doping in the FePt deteriorates the chemical ordering as a result of reduced kinetic energy of FePt adatoms due to frequent collision with carbon adatoms. This leads to a reduction in the magnetocrystalline anisotropy energy and hence the coercivity. RF etching of the MgO/CrRu underlayer before deposition of FePt helps to reduce the grain size and intergranular exchange interaction without adversely affecting the chemical ordering. Reduced intergranular exchange interaction leads to an increase in the coercivity. 相似文献
5.
采用直流磁控溅射的方法制备了一系列(CoPt/Ag)n多层膜,然后在不同温度下 进行了退火处理,并对其结构和磁性做了初步的表征,研究了Ag的含量以及薄膜中每一单元 厚度与总厚度对退火后薄膜的结构以及磁性能的影响.结果表明,膜厚较薄时(大约20 nm)有 利于薄膜沿(001)取向生长,Ag的加入不但能够抑制CoPt晶粒的过分长大还可以诱导薄膜的( 001)取向,使退火后的薄膜在垂直于膜面方向上的矫顽力大大增强.对于特定组分为Co 40Pt43Ag17的薄膜,经600℃退火后已经显示了明显的(001) 取向,垂直于膜面方向上的矫顽力为5.6×105 A/m,饱和磁化强度为0.65T, 并 且磁滞回线具有很好的矩形度,剩磁比(s)为0.95.
关键词:
磁记录材料
磁性薄膜
CoPt/Ag纳米复合膜 相似文献
6.
《Journal of magnetism and magnetic materials》2005,285(3):443-449
The effect of the thickness of Cr90Ru10 underlayers on the microstructure and magnetic properties of FePt films has been studied. Experimental results showed that the FePt films grown on the Cr90Ru10 underlayers exhibited a (0 0 1) preferred orientation with out-of-plane magnetic anisotropy. The degree of the FePt(0 0 1) preferred orientation was closely related to that of the Cr(0 0 2) preferred orientation. The degree of ordering of the FePt films increased with the thickness of the Cr90Ru10 underlayers. The angular dependence of the coercivity curves suggested that an incoherent curling rotational mode be a dominant magnetic reversal mechanism in the FePt films at various Cr90Ru10 underlayer thicknesses. 相似文献
7.
Xu Li Yu-Chi Chang Jiann-Yeu Chen Ko-Wei Lin Ryan D. Desautels Johan van Lierop Philip W.T. Pong 《Physics letters. A》2018,382(39):2886-2893
Exchange-biased bilayers are widely used in the pinned layers of spintronic devices. While magnetic field annealing (MFA) was routinely engaged during the fabrication of these devices, the annealing effect of NiO/CoFe bilayers is not yet reported. In this paper, the transition from NiO/Co90Fe10 bilayer to nanocomposite single layer was observed through rapid thermal annealing at different temperatures under magnetic field. The as-deposited and low-temperature (<623 K) annealed samples had rock salt (NiO) and face center cubic (Co90Fe10) structures. On the other hand, annealing at 623 K and 673 K resulted in nanocomposite single layers composed of oxides (matrix) and alloys (precipitate), due to grain boundary oxidization and strong interdiffusion in the NiO/CoFe and CoFe/SiO2 interfaces. The structural transition was accompanied by the reduction of grain sizes, re-ordering of crystallites, incensement of roughness, and reduction of Ni2+. When measured at room temperature, the bilayers exhibited soft magnetism with small room-temperature coercivity. The nanocomposite layers exhibited an enhanced coercivity due to the changes in the magnetization reversal mechanism by pinning from the oxides. At 10 K, the increased antiferromagnetic anisotropy in the NiO resulted in enhanced coercivity and exchange bias in the bilayers. The nanocomposites exhibited weaker exchange bias compared with the bilayers due to frustrated interfacial spins. This investigation on how the magnetic properties of exchange-biased bilayers are influenced by magnetic RTA provides insights into controlling the magnetization reversal properties of thin films. 相似文献
8.
Xiaoqiang Zhu Zhenkun WangYi Zhang Li XiJianbo Wang Qingfang Liu 《Journal of magnetism and magnetic materials》2012
FeNi thin films were fabricated by radio frequency magnetron sputtering on Si(1 1 1). Dynamic properties at remanence of the films were systematically investigated in a wide frequency range from 100 MHz to 5 GHz. The results show that both thickness of FeNi films and oblique angle have important effects on the magnetic properties of the films, the magnetic resonant frequency of the films can also be adjusted by the two factors. The in-plane uniaxial magnetic anisotropy field can be adjusted from 82 Oe to 220 Oe by increasing the oblique angle. As a consequence, the magnetic resonant frequency of the films increased from 2.7 GHz to 4.2 GHz. 相似文献
9.
X. Wang W. T. Zheng H. W. Tian S. S. Yu W. Xu S. H. Meng X. D. He J. C. Han C. Q. Sun B. K. Tay 《Applied Surface Science》2003,220(1-4):30-39
FeN thin films were deposited on glass substrates by dc magnetron sputtering at different Ar/N2 discharges. The composition, structure and the surface morphology of the films were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM). Films deposited at different nitrogen pressures exhibited different structures with different nitrogen contents, and the surface roughness depended on the mechanism of the film growth. Saturation magnetization and coercivity of all films were determined using superconducting quantum interference device, which showed that if N2/(Ar+N2) flow ratio was equal to or larger than 30% the nonmagnetic single-phase γ″-FeN appeared. If N2/(Ar+N2) flow ratio was less than 10%, the films consisted of the mixed phases of FeN0.056 and γ′-Fe16N2, whose saturation magnetizations were larger than that of -Fe. If N2/(Ar+N2) flow ratio was 10%, the phases of γ′-Fe4N and -Fe3N appeared, whose saturation magnetizations were lower than that of -Fe. 相似文献
10.
用磁控溅射法在单晶MgO(100)基片上制备了[FePt 2 nm/Ag dnm]10多层膜, 经真空热处理后,得到具有高矫顽力的垂直取向L10-FePt/Ag颗粒膜.x射线衍射结 果表明,在250 ℃的热基片上溅射,当Ag层厚度d=3—11 nm时,FePt颗粒具有很好的[001]取向,随着Ag层厚度的增加,FePt颗粒尺寸减小.[FePt 2 nm/Ag 9 nm]10经过6 00 ℃真空热处理15 min后,颗粒大小仅约8 nm,垂直矫顽力达到692 kA/m.这种无磁耦合作用的颗粒膜,适合用作超高密度的垂直磁记录介质.
关键词:
磁控溅射
垂直磁记录
纳米颗粒膜
0-FePt/Ag')" href="#">L10-FePt/Ag 相似文献
11.
Aluminum doped zinc oxide (ZAO) films were deposited by direct current (DC) reactive magnetron sputtering from a ZnO:Al2O3 (3 wt.% Al2O3) ceramic target at room temperature. In order to explore the inhomogeneous property distribution across the substrate, the films were deposited with varied substrate-target distances (Ds) ranging from 2 cm to 9 cm. The experimental results obtained from four-point probe, spectrophotometer, scanning electron microscope, X-ray diffractometer and Auger electronic spectrometer were analyzed to explore the nonuniform property distribution of the obtained ZAO films. The results confirmed that the films’ optoelectronic properties, crystallinity and surface morphology, etc., which were obtained from different substrate areas facing the target were remarkably different. It was revealed that the inhomogeneous property distribution was noticeably dependent on the Ds. It was also suggested that the great difference of electrical conductivity among films from different substrate areas could not be ascribed to the difference of chemical composition, but might be explained by the distinctive crystallinity correspondingly. Films from different substrate regions with distinctive electrical characteristics were either (0 0 2) or (1 1 0) textured. 相似文献
12.
通过射频磁控溅射法制备了Fe_Si_B_Nb_Cu薄膜,采用x射线衍射与Mssb auer谱相结合分析了薄膜的微结构形态,研究了不同溅射功率对薄膜微结构的影响.其结果 表明:在较低溅射功率密度下,薄膜为无定型结构;随着溅射功率密度升高,沉积薄膜无需 热处理,便呈现出晶态和非晶态的混合相结构,晶态为纳米级的α_Fe(Si)和α_Fe(B)固溶 体;α_Fe(Si)相和α_Fe(B)相的体积分数、微结构组态、磁矩取向及宏观磁性能均随着溅 射功率的变化而变化.
关键词:
溅射功率
Fe_Si_B_Nb_Cu合金
薄膜微结构
磁矩取向 相似文献
13.
J.L. Tsai C.J. Hsu Y.H. Pai F.S. Shieu C.W. Hsu S.K. Chen W.C. Chang 《Journal of magnetism and magnetic materials》2006
We have explored the interlayer diffusion effect of Ge/FePt, GePt/FePt bilayer on the formation of ordered L10 FePt phase. In Ge/FePt bilayer, the Ge3Pt2 compound was formed during post annealing at 400oC for 1.0 h. Diffusion between Ge and FePt layer suppres the formation of ordered L10 FePt phase. With Ge2Pt3 underlayer, the FePt film was ordered at 400 °C and the in-plane coercivity was 9.3 kOe. The ordering temperature was reduced about 50 °C compared to the single layer FePt film. 相似文献
14.
This work focuses on the formation mechanisms of nano-island FePt film on commercial copper grids covered with an amorphous carbon film. FePt films of different thickness (1-7.5 nm) were deposited on amorphous carbon film and then post-annealed at 700 °C for 30 min. The configuration of the film was changed during the annealing process due to the surface energy difference between the amorphous carbon films and FePt alloy. We have prepared nanometer-size island-shaped FePt films on the amorphous carbon films and investigated their magnetic properties and microstructures. A discontinuous nano-size island magnetic film can reduce the exchange coupling of the media and increase the recording density. 相似文献
15.
Effects of the Hf content in Co-Hf-Ta thin films on the microstructure and magnetic properties were investigated in this study. It was found that appropriate Hf addition can effectively refine the Co grain size. Co grain sizes sharply decreased from 50 nm down to 2.3 nm with increasing the Hf content from 1.02 at.% to 2.81 at.%, leading to the reduced magneto-crystalline anisotropy. The Co-Hf-Ta thin films with small Co grains reveal low anisotropy field, low coercivity, and high resistivity. By optimizing the Hf content, the film with Hf concentration of 2.81 at.% exhibits excellent soft magnetic properties: high saturation magnetization (4πMS ∼ 13.6 kG), and low coercivity (HC ∼ 0.6 Oe). The effective permeability of the film reaches 800 and remains constant up to 1 GHz. 相似文献
16.
Y.S. Yu Hai-Bo Li W.L. Li Yu-Mei Zhang 《Journal of magnetism and magnetic materials》2010,322(13):1770-1774
Using dc magnetron sputtering, Fe/Pt/Au multilayer films were prepared, and the effects of Au layer thickness and annealing temperature on structure and magnetic properties of the Fe/Pt/Au multilayer films were investigated. The as-deposited Fe/Pt/Au multilayer films have good periodic structure with composition modulation along the growth direction. The stress stored in the as-deposited films promoted the ordering of the films annealed at 400 °C. When the films were annealed at 500 °C, the thicker Au layer could restrain the order-disorder transformation region volume and lead to the decrease of the ordered volume fraction with Au layer thickness increasing. 相似文献
17.
Dan Phuong Nguyen Se-Young O Chan-Woo Park Keesam Shin Chan-Gyu Lee Toshitada Shimozaki Takahisa Okino 《Journal of magnetism and magnetic materials》2008,320(14):e264-e267
[Fe(0.5 nm)/Pt(0.5 nm)]40, [Fe(1 nm)/Pt(1.5 nm)]20 and [Fe(3 nm)/Pt(3 nm)]10 multilayer were prepared by DC magnetron sputtering. By conventional furnace annealing (CA) at 270–600 °C for various time, all of the films still remained the disordered structure with the soft magnetic phase. By rapid thermal annealing (RTA) at 500 °C for various time, we obtained the [Fe(1 nm)/Pt(1.5 nm)]20 and [Fe(3 nm)/Pt(3 nm)]10 films with L12 ordered FePt3 phase which was almost ferromagnetic at room temperature. However, the [Fe(0.5 nm)/Pt(0.5 nm)]40 films was still disordered state even under RTA. Compared with CA, RTA exposed an outstanding effect on accelerating the phase transition when the film thickness is over [Fe(0.5 nm)/Pt(0.5 nm)]40. 相似文献
18.
Structure, microstructure, magnetic properties of 300-nm-thick FePt films with 10-nm-thick Hf underlayer have been studied. The experimental results showed that the very thin Hf underlayer could promote the ordering at reduced temperatures by facilitating the nucleation of the order phase, leading to refined grain size and magnetic domain size. Therefore, the permanent magnetic properties of FePt films were enhanced. (BH)max and Hc of FePt films were greatly enhanced from 5.0–21.0 MGOe and 1.4–11.0 kOe for single layer to 10.2–23.6 MGOe and 4.5–13.2 kOe for Hf-underlayered films annealed in Ta region of 400–600 °C, respectively. Nevertheless, the severe interdiffusion between the Hf and FePt layers at Ta=800 °C resulted in the decreased S, coarsened surface morphology, grain and magnetic domain sizes, and therefore the slightly decreased (BH)max to 18.0 MGOe. 相似文献
19.
20.
Mg-Zr-O protective films for plasma display panels (PDPs) were deposited on soda-lime glass substrates by magnetron sputtering method. The effects of Zr doping on both the discharge properties (firing voltage, Vf and the minimum sustaining voltage, Vs) and the microstructure of the Mg-Zr-O films were investigated. The results show that the deposited Mg-Zr-O films retain the NaCl-type structure as the pure MgO crystal. The doped Zr exists in the form of Zr4+ substitution solution in MgO crystal and an appropriate amount of Zr can improve the surface characteristics of the Mg-Zr-O films effectively. When the Zr atomic concentration is about 2%, the Mg-Zr-O films have the strongest (2 0 0) preferred orientation and the minimum surface roughness. The firing voltage and the minimum sustaining voltage of Mg-Zr-O protective layer are reduced at most by about 25 V and 15 V, respectively, compared with those of the pure MgO film. Mg-Zr-O protective layers with an appropriate amount of Zr are promising to meet the demands of advanced high-vision PDPs. 相似文献