排序方式: 共有29条查询结果,搜索用时 31 毫秒
1.
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 相似文献
2.
采用了熔盐法新工艺制备了纯相与掺钒的MnNb2O6粉晶,利用X射线衍射仪(XRD),扫描电子显微镜(SEM),能谱分析(EDX),透射电子显微镜(TEM)、高分辨透射电镜(HRTEM)和电子衍射(SAED)分析了其物相、形貌及微结构.结果表明合成产物为正交晶系钶铁矿型MnNb2O6;在不同的熔盐中合成出了棒状、片状与长方体形貌的纯相产物.讨论了温度与掺杂对结构与形貌的影响,HRTEM与SAED分析表明了产物的各向异性生
关键词:
熔盐法
结构与形貌
掺杂
反铁磁性 相似文献
3.
用射频磁控溅射技术制备出纳米GaSb颗粒镶嵌在SiO2介质中的复合薄膜.透射电子显微镜观察表明, 纳米GaSb颗粒均匀地镶嵌在SiO2介质中.X射线衍射显示出GaSb (111),GaSb(220) 和GaSb(311)典型的面心立方闪锌矿结构特征.复合薄膜的室温光吸收谱表明,吸收边发生了较大的蓝移,并且,蓝移量随纳米GaSb的颗粒尺寸减小而增大.复合薄膜的室温Raman光谱表明: 薄膜的Raman散射峰较块体材料的有较大的红移和宽化.用量子限域理论和张应力效应对这些现象作了解释. 相似文献
4.
N vacancy,substitutional O,and Al defects in the bandgap of composition-tunable nonstoichiometric AlN powder 下载免费PDF全文
AlN powders are prepared by direct nitridation via Al liquid and vapor phases in mixed atmospheres of N2and NH3with different NH3/N2ratios. The reaction analysis reveals that NH3acts as catalyst for N2dissociation and the transportations of N, O, and Al in the liquid phase are different from those in the vapor phase. Accordingly, the products are Al-rich and composition-tunable nonstoichiometric AlN in which N, O, and Al content values change with nitridation atmosphere and temperature, leading to the variation of the relevant defect concentration. Therefore, the AlN powders exhibit prominent absorption bands around 5.30, 3.40, and 1.50 eV, which are tentatively assigned to VN, ONdonors, and AlNacceptor respectively. Furthermore, a new donor named [VN–ON] complex is predicted at 4.40 eV within the 5.90 eV bandgap. It is demonstrated that the optical spectra of nonstoichiometric AlN are preferable to the nominal stoichimometric one for the identification of the defects energy level. 相似文献
5.
The Raman shifts of nanocrystalline GaSb excited by an Ar^ ion laser at wavelengths 514.5, 496.5, 488.0, 476.5,and 457.9nm are studied by an SPEX-1403 laser Raman spectrometer respectively, and they are explained by phonon confinement, tensile stress, resonant Raman scattering and quantum size effects. The Stokes and anti-Stokes Raman spectra of GaSb nanocrystals strongly support the Raman feature of GaSb nanocrystals. The calculated optical spectra compare well with experimental data on Raman scattering GaSb nanocrystals. 相似文献
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7.
Structure, room-temperature magnetic and optical properties of Mn-doped TiO2 nano powders prepared by the sol-gel process 下载免费PDF全文
TiO 2 nano powders with Mn concentration of 0 at%-12 at% were synthesized by the sol-gel process,and were annealed at 500 C and 800 C in air for 2 hrs.X-ray diffraction (XRD) measurements indicate that the Mn-TiO 2 nano powders with Mn concentration of 1 at% and 2 at% annealed at 500 and 800 C are of pure anatase and rutile,respectively.The scanning electron microscope (SEM) observations reveal that the crystal grain size increases with the annealing temperature,and the high resolution transmission electron microscopy (HRTEM) investigations further indicate that the samples are well crystallized,confirming that Mn has doped into the TiO 2 crystal lattice effectively.The room temperature ferromagnetism,which could be explained within the scope of the bound magnetic polaron (BMP) theory,is detected in the Mn-TiO 2 samples with Mn concentration of 2 at%,and the magnetization of the powders annealed at 500 C is stronger than that of the sample treated at 800 C.The UV-VIS diffuse reflectance spectra results demonstrate that the absorption of the TiO 2 powders could be enlarged by the enhanced trapped electron absorption caused by Mn doping. 相似文献
8.
采用溶胶-凝胶法制备出钙钛矿型纳米BaFeO3粉末,利用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析研究了其微观结构及形貌,结果表明:胶体试样经800℃退火处理后,形成了20nm左右的钙钛矿型BaFeO3粉末,其(110)面晶面间距为0.280nm左右,(100)面晶面间距为0.401nm左右.利用振动样品磁强计(VSM)研究了纳米BaFeO3粉末的室温铁磁性能,测量结果表明:在室温条件下,纳米BaFeO关键词:
溶胶-凝胶法
3')" href="#">钙钛矿型纳米BaFeO3
铁磁性
氧空位 相似文献
9.
用射频磁控溅射技术制备出纳米GaSb颗粒镶嵌在SiO2 介质中的复合薄膜 .透射电子显微镜观察表明 ,纳米GaSb颗粒均匀地镶嵌在SiO2 介质中 .X射线衍射显示出GaSb ( 1 1 1 ) ,GaSb ( 2 2 0 )和GaSb ( 31 1 )典型的面心立方闪锌矿结构特征 .复合薄膜的室温光吸收谱表明 ,吸收边发生了较大的蓝移 ,并且 ,蓝移量随纳米GaSb的颗粒尺寸减小而增大 .复合薄膜的室温Raman光谱表明 :薄膜的Raman散射峰较块体材料的有较大的红移和宽化 .用量子限域理论和张应力效应对这些现象作了解释 . 相似文献
10.
N vacancy,substitutional O,and AI defects in the bandgap of composition-tunable nonstoichiometric AIN powder 下载免费PDF全文
AlN powders are prepared by direct nitridation via Al liquid and vapor phases in mixed atmospheres of N2 and NH3 with different NH3/N2 ratios. The reaction analysis reveals that NH3 acts as catalyst for N2 dissociation and the transportations of N, O, and Al in the liquid phase are different from those in the vapor phase. Accordingly, the products are Al-rich and composition-tunable nonstoichiometric AlN in which N, O, and Al content values change with nitridation atmosphere and temperature, leading to the variation of the relevant defect concentration. Therefore, the AlN powders exhibit prominent absorption bands around 5.30, 3.40, and 1.50 eV, which are tentatively assigned to VN, ON donors, and AlN acceptor respectively. Furthermore, a new donor named [VN-ON] complex is predicted at 4.40 eV within the 5.90 eV bandgap. It is demonstrated that the optical spectra of nonstoichiometric AlN are preferable to the nominal stoichimometric one for the identification of the defects energy level. 相似文献