Materials
·
2023
·Vol. 16
·期 9
·3395
·
IF 3.4
Mingheng Mao,Shaoqiu Ke,Dingguo Tang,Xiahan Sang,Danqi He
Co magnetic films are widely used in high-frequency magnetic recording and vertical magnetic recording due to their high saturation magnetization and magnetocrystalline anisotropy. In this work, ferromagnetic Co magnetic films were prepared on copper substrate by vacuum evaporation combined with heat treatment (H2atmosphere), to investigate the impact of film thickness and annealing temperature on microstructure and magnetic properties. The results show that with the increase in annealing temperature, the Co thin film physical phase does not change significantly, the crystallinity increases, and the grain size increases, which is consistent with the results obtained from the SEM morphology map of the sample surface, leading to an increase in coercivity. By annealing experiments (atmospheric atmosphere) on Co magnetic films with and without an Al protective layer, as shown by scanning electron microscopy microscopic characterization results, it was verified that the Al layer can protect the inner Co layer from oxidation. As the film thickness increases from 10 to 300 nm, the magnetic properties of Co films change significantly. The saturation magnetization gradually increases from 0.89 to 5.21 emu/g, and the coercivity increases from 124.3 to 363.8 Oe. The remanence ratio of the 10 nm magnetic film is 0.82, which is much higher than the film remanence ratio of 0.46 at 50 nm. This is because when the thickness of the film is between 10 and 50 nm, the magnetic moments partially deviate from the in-plane direction, and the out-of-plane component reduces the film remanence ratio. This study shows that optimizing annealing temperature and film thickness can effectively control the structure and magnetic properties of Co magnetic films, which is of great significance for the development of the magnetic recording field.Keywords:magnetic films;annealing;vacuum evaporation coating;remanence ratio
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2024
·
IF 5.8
Juanjuan Wang,Bin Qin,Huirong Li,Yuxin Zhang,Huan Yang,Fang Wang
Ferromagnetic Cr2Te3 nanocrystals, with their high spin–orbit coupling and low symmetry, have attracted considerable attention as rare-earth-free magnetic nanomaterials due to their potential to achieve high magnetic anisotropy. However, their relatively low values of remanence (Mr) and saturation (MS) magnetisation limit their energy product, making them unsuitable for practical applications. Herein, we report a straightforward one-pot heat-injection technique for the synthesis of high-remanence hexagonal Cr2Te3 nanosheets by heterogeneous doping with atoms of M (M = V, Mn and Se). The doped materials provide enhanced Mr and MS at an unchanged Curie temperature (TC), resulting in excellent hard magnetic properties. With Mn doping, the Mr of the matrix increases significantly, reaching 18.38 emu g−1 at 5 K, far exceeding the original undoped Cr2Te3 nanosheets. The nearly square hysteresis loop makes it valuable for many low temperature applications. These results provide a valuable case for tuning the magnetism of ferromagnetic Cr2Te3 by substitutional doping.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FERROELECTRICS
·
2021
·
IF 0.62
Huiting Liu,Chengzhi Lu,Dun Wu,Chunlin Liu,Zheng Cao,Junfeng Cheng
Acrylic resin and PLZT (Pb0.910La0.060 (Zr0.580Ti0.420)0.975Nb0.020O3.000) powder were mixed to prepare PLZT/acrylic resin thermosetting feedstock. Injection molding is used to form high-strength PLZT piezoelectric ceramic embryos then sintered to piezoelectric materials. The experimental results showed that the residual polarization is higher at 85% solid content of the feed and the d33 value increased. And the PLZT powder coated with stearic acid can improve the piezoelectric and ferroelectric properties of powder injection molded piezoelectric ceramics. Tests above are intended to provide preliminary exploration for thermal curing injection molding and thermal curing 3 D printing piezoelectric ceramics.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 24
·20970-20978
·
IF 2.195
Gong Pengyu,Chen Qingyun,Shih Kaimin,Liao Changzhong,Wang Lielin,Xie Hua,Deng Sihao
The structure and magnetic properties of the magnetite can be substantial corrected by incorporating foreign cations. In this work, Tb 3+ was successfully incorporated into magnetite and superparamagnetic magnetite nanoparticles were obtained, using solvothermal method. The doping of Tb 3+ greatly reduces the M r and H c values of the magnetite. Due to the doping of high magnetic moment Tb 3+ , the original magnetic moment of the magnetite is destroyed and magnetic domain are decomposed, resulting in a significant reduction in remanence and magnetic agglomeration. The remarkable effect of Tb 3+ doping degaussing will provide new prospects for the application of magnetite materials in the superparamagnetic direction.
研究领域:
材料科学
·
纳米技术
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Bin Xie,Xiaoyuan Zhou,Wei Chen,Lining Fan,Lixin Zhang,Runqiu Li,Hui Zheng,Qiong Wu,Yanhui Wu,Yaning Lin,Peng Zheng,Liang Zheng,Yang Zhang
A high remanence ratio of hexagonal barium ferrite film is urgently needed for self-biased microwave devices. In this work, the aluminum-substituted hexagonal barium ferrite films (BaFe (12−x) Al x O 19 ) with different substituting concentrations (x = 0, 1.5, 2, 2.5, 3) were deposited on the Al 2 O 3 substrate by pulsed laser deposition method using self-sintered BaFe (12−x) Al x O 19 target. Firstly, the targets with different Al concentrations were sintered by the solid phase method and exhibited high dense, uniform microstructure, and high purity. Then, the influence of the Al ions concentration on the crystal structure, morphology, and magnetic and microwave properties of BaFe (12−x) Al x O 19 films was studied in detail. Structural characterizations confirm that the Al prefers to substitute for 2a, 4f2 and 2b sites and promotes the grain (formed as single-domain) orientation growth, which results in a decrease in the saturation magnetization, an increase of remanence ratio and anisotropy field. Consequently, a high remanence ratio of 95 % was obtained for BaFe (12−x) Al x O 19 film at x = 3, and also displays a high anisotropy field (27.7 kOe), a low saturation magnetization (1758 G) and an appropriate ferromagnetic resonance linewidth (～436 Oe), which can be applied in self-biased devices.
研究领域:
材料科学
·
磁学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Advances
·
2024
·
IF 8.1
Ting Sai,Pengfei Wang,Xiaoying Gu,Xueping Xu,Jinji Sun,Jing Ye
Cobalt-based amorphous alloys (Co-MG) demonstrate ultra-high permeability and remarkably-low power loss, positioning them as promising candidates for shielding (near-) static magnetic fields and addressing accuracy limitations in extremely-weak magnetic measurements. However , the brittleness and poor understanding about magnetic performance below 100 Hz have impeded their widespread adoption. To integrate satisfied processing, magnetic and mechanical performances, polystyrene-grafted Co-MG composites are developed. Compared with permalloy-1J85, Co-MG-( g -PS_35 %) composite exhibits 40 % increase in initial permeability, 48 % increase in saturation magnetization, 71 % reduction in remanence within shielding area. In contrast to Mn–Zn ferrite, Co-MG-( g -PS_35 %) composite demonstrates the power loss and μ ″/ μ ′ 2 values lower by an order of magnitude, resulting in magnetic noises 85 % lower at 1 Hz. Furthermore, the resultant composite maintains similar processing-rheological behaviors and mechanical properties compared with bulk polystyrene. It provides an innovative solution to expand real-world applications for biomagnetic detection, and overcome the sensitivity limitation of extremely-weak magnetic measurement.
研究领域:
材料科学
·
磁学
·
复合材料
·
生物磁检测
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）