Co离子注入TiO2薄膜的显微结构和磁性研究

利用直流磁控溅射技术在玻璃衬底上沉积了TiO₂薄膜,并对其进行了Co离子注入,最后在真空中500 ℃退火50 min,得到系列薄膜样品. 利用剥离-分散方法制备了薄膜的透射电镜样品,并用扫描电镜(SEM)、X射线能量散射谱(EDX)和高分辨透射电镜(HRTEM)对样品做了近似原位观察,研究了薄膜样品中不同Co离子注入深度的成分分布和显微结构. 结果表明,薄膜呈锐钛矿结构,Co元素主要分布在薄膜表层,Co离子的注入使TiO₂薄膜的晶粒被部分破坏,并形成CoO,而5 关键词： 2薄膜')" href="#">Co注入TiO₂薄膜 电镜原位观察 室温铁磁性     

Electrical conduction and optical properties of amorphous (Sb2Se3)100−xSnx thin films

The variation of DC electrical conductivity and the optical properties of thermally evaporated a- (Sb₂Se₃)_100−xSn_x thin films with temperature have been studied. It is found that the thermal activation energy decreases, while the optical gap first increases (up to x=1) and then decreases, with the increase in Sn content. These results have been explained by taking into consideration the structural modifications induced by the incorporation of Sn into the parent alloy. The variation in the conductivity prefactor (σ_o) with Sn addition indicates a change in the dominant conduction transport mechanism from extended states to localized states. An experimental correlation between the activation energy and the pre-exponential factor has been observed, indicating the validity of Meyer–Neldel rule in the studied samples.     

Thickness-dependent electrical and optical properties of Ge8Sb2Te11 thin films

The amorphous Ge₈Sb₂Te₁₁thin films with varying thickness are thermally deposited on well-cleaned glass substrate from its polycrystalline bulk. Absence of any sharp peak confirms the amorphous nature of deposited films. Thickness-dependent electrical and optical properties including dc-activation energy, sheet resistivity, optical band gap, band tailing parameter, etc. of Ge₈Sb₂Te₁₁thin films have been studied. The optical parameters have been calculated from transmission, reflection and absorbance data in the spectral range of 200–1100 nm. It has been found that optical band gap and band tailing parameter decreases with the increase in Ge₈Sb₂Te₁₁thin films thickness. The dc-activation energy and sheet resistivity decreases while the crystallization temperature of the amorphous Ge₈Sb₂Te₁₁ films increases with the increase in thickness of the films. The decrease of the sheet resistivity has been substantiated quantitatively using the classical size-effect theory. These results have been explained on the basis of rearrangements of defects and disorders in the amorphous chalcogenide system.     

Deposition of ZnS thin film by ultrasonic spray pyrolysis: effect of thickness on the crystallographic and electrical properties

Zinc sulfide (ZnS) thin films have been deposited on Si (1 0 0) substrate using ultrasonic spray pyrolysis. X-ray diffraction (XRD) analysis revealed that the films are (0 0 2) preferentially oriented with c-axis-oriented wurtzite structure. The crystallinity has been found to improve with film thickness in the 180–6000 nm range. Film structure has been analyzed by XRD, scanning electron microscope, FTIR, and Raman spectroscopies, while the stoichiometry has been verified by energy-dispersive spectroscopy and particle-induced X-ray emission techniques. Electrical properties of the grown films were characterized by current–voltage and capacitance–voltage measurements where, the films show better conducting behavior at higher thickness.     

LB薄膜中四新戊氧基酞菁锌和四壬基酞菁铜分子聚集体的吸收光谱的温度特性

本文制备了四新戊氧基酞菁锌(Tetra-neopentoxy phthalocyanine zine)(TNPPeZn)和四壬基酞菁铜(Tetra-nonyl phthalocyanine copper)(TNPeCu)两种酞菁衍生物的Langmuir-Blodgett(LB)薄膜.通过测量10～473K温度下的吸收光谱,研究了两种薄膜的分子聚集状态.TNPPeZn的LB薄膜中,存在着分子单体和分子二聚体,在吸收光谱中分别表现为680nm和620nm的吸收峰.随着温度的升高,分子单体逐渐转变为分子二聚体,这个过程是不可逆的.TNPeCu的LB薄膜中,除了分子单体和分子二聚体以外,还有吸收为740nm的分子J聚集体存在.随着温度的变化,J聚集体发生可逆变化.     

射频功率对类金刚石薄膜性能的影响

在不同射频功率条件下,实验研究了射频等离子体化学气相沉积类金刚石薄膜的金刚石相分数、光学常数和硬度。利用Raman光谱仪、椭圆偏振仪、数字式显微硬度计分别测试了不同条件下单层类金刚石薄膜的金刚石相分数、光学常数和硬度。实验表明,随着功率的增加,金刚石相的相对分数减少,薄膜的折射率先减小再增加然后减小,射频功率大于910 W时,沉积速率急剧增大。而薄膜的硬度先增加后减小,在射频功率为860 W处获得最大值。     

ZnTe（ZnTe：Cu）多晶薄膜的XPS研究

用共蒸发法在室温下制备了ZnTe及ZnTe：Cu多晶薄膜，测量了电导率温度曲线，发现不掺杂的ZnTe薄膜的暗电导随温度的增加而线形增加，呈常规的半导体材料特征；掺Cu的ZnTe薄膜在温度较低时，lnσ随温度升高而缓慢增加，随后缓慢降低，达到一极小值，当温度继续升高时又陡然增加，呈现异常现象。用XPS研究了N2气氛下退火前后表面状态，发现不掺Cu的ZnTe薄膜呈现富Te现象。掺Cu后Te氧化明显，以ZnTe形式存在的Te明显减少；ZnTe：Cu薄膜中Zn的含量在退火前后变化明显，退火前，Zn主要以ZnTe形式存在，退火后Zn原子向表面扩散，使表面成分更加均匀，谱峰变宽；退火时，部分Cu原子进入晶格形成CuxTe相，引起载流子浓度变化，导致ZnTe：Cu多晶薄膜的电导温度关系异常。     

激光刻蚀银纳米粒子岛膜的SERS特性

利用激光刻蚀的方法,通过改变激光脉冲的能量,制备出一系列的纳米金属银胶体。将银胶体沉积在铝基底上形成一层银岛膜。用紫外—可见吸收光谱、SEM及拉曼光谱对银胶体和银岛膜进行了表征。研究结果表明,刻蚀所用激光脉冲的能量影响胶体中银颗粒的分布;不同能量下制备的胶体所形成的银岛膜具有不同的表面增强效果;该岛膜具有增强效果优异、制备简便等特点。     

不同掺杂的钇系-123薄膜磁通特性

我们在磁场中分别测量了最佳掺杂的YBa2Cu3O7-δ、钙0．2掺杂的Y1-xCaxBa2Cu3O7-δ及钙0．5掺杂的Pr1-xCaxBa2Cu3O7-δ薄膜的电阻温度关系．利用最近Zhang et al.[Phys．Rev．B71（2005），052502]提出的热激活能的分析方法对薄膜的磁通特性进行了分析、比较与讨论．