膜厚对NiO/NiFe/Cu/NiFe磁阻效应的影响

用射频磁控溅射方法制备多层膜,研究了双层膜ＮｉＯ／ＮｉＦｅ的矫顽力Ｈｃ和交换耦合场Ｈｅｘ与反铁磁层ＮｉＯ、铁磁层ＮｉＦｅ厚度的关系,结果表明：ＮｉＯ厚度为７０ｎｍ时,Ｈｅｘ最大;Ｈｃ随ＮｉＯ厚度增大而增大．当ＮｉＦｅ厚度增加时,Ｈｅｘ近似线性减小;而Ｈｃ则随ＮｉＦｅ厚度增大开始有缓慢增加,然后才减小．对于ＮｉＯ（７０ｎｍ）／ＮｉＦｅ（ｔ１）／Ｃｕ（２．２ｎｍ）／ＮｉＦｅ（ｔ２）自旋阀多层膜材料（括号内的量表示厚度）,研究了ＮｉＦｅ膜厚度对磁阻效应的影响,结果表明：被钉扎层ＮｉＦｅ的厚度为３ｎｍ,自由层ＮｉＦｅ的厚度为５ｎｍ时,ＭＲ值最大,约为１．６％．     

巨磁电阻自旋阀多层膜的结构和磁性

用磁控溅射镀膜方法，制成了巨磁电阻自旋阀多层膜Ｔａ／ＮｉＦｅ／Ｃｕ／ＮｉＦｅ／ＦｅＭｎ／Ｔａ。它具有优良的特性。其室温磁电阻比率ＭＲ〉２％，自由层矫元力Ｈｃｌ〈１６０Ａ／ｍ，自由层零磁场漂Ｈｆ〈８００Ａ／ｍ和钉 扎层交换场Ｈｅｘ≈２０×１０＾３Ａ／Ｍ。     

阴极共沉积Ni（OH）2薄膜在碱淀粉液中的电化学特性

采用阴极电沉积法在镍基底上制备Ｎｉ（ＯＨ）薄膜,循环伏安法在１．０ｍｏｌ．ｄｍ＾－３ＫＯＨ溶液中测量了薄膜电极的催化析氧特性,沉积Ｎｉ（ＯＨ）２的薄膜电极比镍基底增加了２０ｍＡ．ｃｍ＾－２的析氧电流。在制膜过程中掺杂７％Ｃｅ（Ｖ／Ｖ）得到的复合氢氧化镍薄膜电极在碱溶液中的析氧电流又增加了约２０ｍＡ．ｃｍ＾－２,分光光度法和薄层扫描分析法对薄膜进行了成分分析。     

NiCr合金基底上离子源辅助激光制备CeO2薄膜及其？…

室温下在ＮｉＣｒ合金（Ｈａｓｔｅｌｌｏｙ ｃ－２７５）基底上应用Ａｒ＾＋离子源辅助,准分子脉冲激光沉积了ＣｅＯ２薄膜。结果表明：在合适的外部条件控制下,直接在ＮｉＣｒ合金基底上可以制备以ｃ－轴取向的ＣｅＯ２薄膜,但这时的ＣｅＯ２薄膜在其ａ－ｂ平面内没有观察到织构的信息;进一步在相同的条件下,首先在ＮｉＣｒ合金基底上制备一层ＹＳＺ（Ｙｔｔｒｉａ－Ｓｔａｂｉｌｉｚｅｄ Ｚｉｒｃｏｎｉａ）,再在ＹＳＺ／     

原位反应生成Al-Fe/Al_2O_3,Al-Cu/Al_2O_3复合材料的过程原理

采用喷射共沉积法制备了Ａｌ－Ｆｅ２Ｏ３及Ａｌ－ＣｕＯ复合体，Ｆｅ和Ｃｕ的质量分数分别为９．６０％和５．５０％．在热处理过程中，随着温度由６００℃升高到８００℃和１０００℃，Ｆｅ３Ｏ４按Ｆｅ３Ｏ４ＦｅＯＦｅ顺序被还原，得到Ａｌ－Ｆｅ／Ａｌ２Ｏ３复合材料，其中Ｆｅ以Ａｌ１３Ｆｅ４相及ＡｌＦｅ相形式存在．Ａｌ２Ｏ３粒度为２～４μｍ均匀分布在基体中．Ａｌ／ＣｕＯ复合体在９００℃处理后，形成Ａｌ－Ｃｕ／Ａｌ２Ｏ３复合材料．文中对显微结构形成、反应进行的过程作了分析．     

氧化镍在γ－Al_2O_3和TiO_2－Al_2O_3上的分散状态研究

采用浸渍法制备了系列ＮｉＯ／γ－Ａｌ２Ｏ３，ＮｉＯ／ＴｉＯ２－Ａｌ２Ｏ３催化剂样品，用ＸＲＤ，ＥＸＡＦＳ等方法对这些样品进行了分析．ＸＲＤ相定量方法测得ＮｉＯ在γ－Ａｌ２Ｏ３载体上的最大分散量为０．０６５ｇＮｉＯ／１００ｍ２Ａｌ２Ｏ３，而ＮｉＯ在ＴｉＯ２－Ａｌ２Ｏ３载体上的最大分散量为０．０８１ｇＮｉＯ／１００ｍ２ＴｉＯ２Ａｌ２Ｏ３。ＥＸＡＦＳ分析结果表明：ＴｉＯ２的引入改变了ＮｉＯ在载体表面上的分散状态．     

用于高频磁阻抗效应的软磁薄膜研究

讨论了用于高频磁阻抗效应传感技术的ＮｅＦｅ软磁薄膜制备和薄膜单轴各向异性产生方法及机理．用射频磁控溅射法在几十ｋＡ／ｍ磁场定向下制备出具有一定单轴各向异性的Ｎｉ８１Ｆｅ１９软磁薄膜,并对所测得的薄膜各种磁化曲线进行了分析     

平果铝厂赤泥的物相分析

采用等离子光谱、Ｘ射线衍射、电子显微分析技术研究了平果铝厂赤泥的化学组成和物相组成．结果表明，平果铝土矿拜耳法处理后的赤泥中含赤铁矿（α－Ｆｅ２Ｏ３）、针铁矿（α－ＦｅＯＯＨ）、水化石榴石（Ｃａ３ＡｌＦｅ（ＳｉＯ４）（ＯＨ）８）、一水硬铝石（Ａｌ２Ｏ３·Ｈ２Ｏ）、含水铝硅酸钠（Ｎａ２Ｏ·Ａｌ２Ｏ３·１．６８ＳｉＯ２·１．７３Ｈ２Ｏ）、钙钛矿（ＣａＴｉＯ３）、羟钙石（Ｃａ（ＯＨ）２）、方解石（ＣａＣＯ３）等物相，其中赤铁矿和水化石榴石含量较高，赤泥中还含有可供工业提纯价值的Ｚｒ，Ｖ，Ｎｂ，Ｔａ，Ｓｃ．研究结果为今后开发利用平果铝厂赤泥提供了理论和实验的依据     

烧结钕铁硼磁体的热处理研究

系统研究了富Ｎｄ的ＮｄｘＦｅ９３－ｘＢ７（ｘ＝１６～２８）烧结磁体的热处理。磁体经低于６５０℃的热处理后，矫顽力显著提高，同时主相晶间出现ＮｄＦｅ２Ｏｘ相，热处理后矫顽力的增加由反向畴形核场的提高和ＮｄＦｅ２Ｏｘ相对反向畴壁钉扎场的增大共同贡献。     

Fe—Ni／Cu磁性多层膜中层间耦合和磁性的研究

利用振动样品磁强计和电子顺磁共振谱仪研究了Ｆｅ－Ｎｉ／Ｃｕ多层膜中的层间耦合和二维效应，以及它们对磁性的影响，对于Ｆｅ－Ｎｉ（３．０ｎｍ）／Ｃｕ多层膜，面内饱和场Ｈｓ，矫顽力Ｈｃ，剩磁比均随Ｃｕ层厚度作同步振荡变化，对于Ｆｅ－Ｎｉ（２．０ｎｍ）／Ｃｕ和Ｆｅ－Ｎｉ（３．０ｎｍ）／Ｃｕ多层膜，有效饱和磁化强度与共振线宽ΔＨ，随Ｃｕ层厚度作同步振荡变化。在它们的铁磁共振谱中，除了一致进动共振模外，还存在     

磁性多层膜Ta/NiO/NiFe/Ta角分辨XPS

磁性多层膜Ta/NiO/NiFe/Ta由磁控溅射方法制备.采用角分辨X射线光电子能谱(XPS)研究了反铁磁(NiO)/铁磁(NiFe)界面.结果表明,在NiO/NiFe界面发生了化学反应: NiO+Fe = Ni+FeO和3NiO+2Fe =3Ni+Fe2O3,此反应深度约为1～1.5 nm.反应产物将影响NiO对NiFe的交换耦合.     

Magnetic property and interface structure of Ta/NiO/NiFe/Ta

Ta/NiO/NiFe/Ta multilayers, utilizing Ta as buffer layer, were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field between NiO and NiFe reached a maximum value of 9.6×10³ A/m at a NiO film thickness of 50 nm. The composition and chemical states at interface region of Ta/NiO/Ta were studied by using the X-ray photoelectron spectroscopy (XPS) and peak decomp- osition technique. The results show that there is an “inter- mixing layer” at the Ta/NiO (and NiO/Ta) interface due to a thermodynamically favorable reaction 2Ta + 5NiO = 5Ni + Ta₂O₅. This interface reaction has a great effect on exchange coupling. The thickness of Ni+NiO estimated by XPS depth- profiles is about 8—10 nm.     

NiO靶烧结温度对NiO/Ni81Fe19双层膜的影响

在不同的温度下烧结制备 Ni O靶 ,用射频磁控溅射法淀积 Ni O/ Ni81 Fe1 9双层膜 ,研究了不同的温度烧结 Ni O靶对 Ni O/ Ni Fe双层膜特性的影响 ,结果表明 ,使用不同的烧结温度制备的 Ni O靶溅射所得的 Ni O膜中 Ni的化学价态及其含量不同 ,进而影响 Ni O/ Ni81 Fe1 9双层膜的磁滞回线的矩形度及层间交换耦合作用     

Effect of Cu surface segregation on the exchange coupling field of NiFe/FeMn bilayers

The NiFe/FeMn bilayers with different buffer layers (Ta or Ta/Cu) were prepared by magnetron sputtering. Results show that the exchange coupling field of NiFe/FeMn films with Ta buffer is higher than that of the films with Ta/ Cu buffer. We analysed the reasons by investigating the crystallographic texture, surface roughness and surface segregation of both films, respectively. We found that the decrease of the exchange coupling fields of NiFe/FeMn films with Ta/ Cu buffer layers was mainly caused by the Cu surface segregation on NiFe surface.     

表面活性剂Bi对自旋阀多层膜交换耦合场的影响及其微结构分析

采用磁控溅射方法制备了Ta(10nm)/NiFe(8nm)/Cu(2.6nm)/NiFe(3.6nm)/FeMn(9nm)/Ta(10nm)自旋阀多层膜.在Cu/NiFe界面沉积适量厚度的Bi原子能够有效地提高交换耦合场,沉积过量的Bi原子会导致交换耦合场下降.X射线光电子能谱分析结果表明:沉积在Cu/NiFe界面的Bi原子可以有效地抑制Cu原子在NiFe层表面的偏聚;当沉积过量的Bi原子时,Bi原子会进一步迁移到FeMn中,形成杂质,从而破坏了FeMn的反铁磁性,使交换耦合场降低.     

Chemical states of the atoms in magnetic multilayersTa/NiOx/Ni81Fe19/Ta and Co/AlOx/Co

Ta/NiOx/Ni81Fe19/Ta and Co/AiOx/Co multilayers were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field (Hex) and the coercivity (Hc)of NiOx/Ni81Fe19 as a function of the ratio of Ar to O2 during the deposition process were studied. The composition and chemical states at the interface region of NiOx/NiFe were also investigated using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that when the ratio of Ar to O2 is equal to 7 and the argon sputtering pressure is 0.57 Pa, the x value is approximately 1and the valence of nickel is +2. At this point, NiOx is antiferromagnetic NiO and the corresponding Hex is the largest.As the ratio of Ar/O2 deviates from 7, the Hex will decrease due to the presence of magnetic impurities such as Ni+3 or metallic Ni at the interface region of NiOx /NiFe, while the Hc will increase due to the metallic Ni. Al layers in Co/AIOx/Co multilayers were also studied by angle-resolved XPS. Our finding is that the bottom Co could be completely covered by depositing an Al layer about 1.8 nm. The thickness of AIOx was 1.2 nm.     

不同过渡层和电场方向对碳纳米管或纤维生长的影响

利用等离子体增强化学气相沉积系统沉积了碳纳米管或纤维，并用扫描电子显微镜研究了它们的生长和结构．为避免碳纳米管或纤维在生长过程中从衬底Si表面上脱落，先在Si表面上溅射沉积了金属过渡层Ti或Ta，然后再沉积催化剂NiFe．结果发现Ti和Ta过渡层对碳纳米管或纤维的结构有很大的影响．另外，还发现衬底Si放在支架的不同位置，碳纳米管或纤维的生长方向不同，这可能是由于辉光放电产生的非均匀电场所致．对不同过渡层和电场方向对碳纳米管或纤维生长的影响进行了分析和讨论．     

SiO2/Ta interface reaction in magnetic multilayers and its influence on Ta buffer layers

Ta is often used as a buffer layer in magnetic multilayers. In this study, Ta/Ni81Fe19/Ta multilayers were deposited by magnetron sputtering on sing-crystal Si with a 300-nm-thick SiO2 film. The composition and chemical states at the interface region of SiO2/Ta were studied using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that there is an "intermixing layer" at the SiO2/Ta interface due to a thermodynamically favorable reaction: 15 SiO2 + 37 Ta = 6 Ta2O5 + 5 Ta5Si3. Therefore, the Ta buffer layer thickness used to induce NiFe (111) texture increases.