NiMn2O4纳米粉体的制备

用溶胶－凝胶法（ｓｏｌ－ｇｅｌ）合成ＮｉＭｎ２Ｏ４纳米级粉体，利用差热分析（ＤＴＡ），热失重（ＴＧ），Ｘ射线衍射（ＸＲＤ），透射电子显微镜（ＴＥＭ）等广阔博征合成过程及纳米粉体的结构，研究结果表明，ＮｉＭｎ２Ｏ４纳米粉体相合成温度比传统固相反应方法合成温度低大约３００℃，粉体的形状呈多面体形。     

溶胶－凝胶法制备MoO_3陶瓷薄膜

以用酸钠为原料，乙二醇为溶剂，用溶胶－凝胶法制备ＭｏＯ３薄膜通过对干凝胶粉做ＤＴＡ和ＴＧ分析，用ＳＥＭ和ＸＲＤ分析还胶膜、热处理后氧化物膜及多次重复浸涂热处理薄膜的显微结构和晶相组成，研究了氧化物薄膜的形成过程．重复４次浸涂热处理可得到约２μｍ厚连续致密的、主晶相为择优取向的斜方ＭｏＯ３薄膜．     

溶胶—凝胶法制备MoO3陶瓷薄膜

以钼酸铵为原料，乙二醇为溶剂，用溶胶－凝胶法制备ＭｏＯ３薄膜，通过对干凝胶粉做ＤＴＡ和ＴＧ分析，用ＳＥＭ和ＸＲＤ分析胶膜，热处理后氧化物膜多次重复浸涂热处理薄膜的显微结构和晶相组成，研究了氧化物薄膜的形成过程，重复４次浸涂热处理可得到的约２μｍ厚连续臻密的，主晶相为择优取向的斜方ＭｏＯ３薄膜。     

Fe77Cr7B16非晶晶化过程居里温度与显微结构的关系

Ｆｅ７７Ｃｒ７Ｂ１６非晶进行一系列热处理，用Ｘ射线衍射、ＴＥＭ考察了各样品的居里化程度（０－１００％），测量了各样吕的居里温度ＴＣ，实验结果表明Ｆｅ７７Ｃｒ７Ｂ１６非晶的晶化是成核长大过程，晶体分数的对数随晶化温度和升高直线增长。晶化相出现前的低温退火处理，样品的ＴＣ不变化。晶化温度以上，非晶基体的ＴＣ随晶化分数的增大而逐渐升高。     

Fe73.5Cu1Mo3Si13.5B9非晶合金的晶化动力学

用ＤＴＡ，结合ＸＲＤ，ＴＥＭ研究了Ｆｅ７３．５Ｃｕ１Ｍｏ３Ｓｉ１３．５Ｂ９软磁非晶合金的晶化动力学，结果表明，该合金在４７８℃时析出ａ－Ｆｅ相，晶化初期激活能量最小（１４８ｋＪ．ｍｏｌ＾－１），它随晶化学量的增加而增大，在ＸＣ为５０－７８％时，呈极大值（５１０ｋＪ．ｍｏｌ＾－１）随退火温度的升高，α－Ｆｅ相的数目增多，但尺寸基本不变。为１４－１６ｍｍ。     

SiC纤维／LAS复合材料的TG－DTA－MS研究

本文首次用ＴＧ－ＤＴＡ－ＭＳ联用技术对ＳｉＣ纤维／ＬＡＳ微晶玻璃复合材料的热分解过程、机制及其与晶化的关系进行了研究。提出了该复合材料界面形成碳层的热力学和质谱分析判别依据，并对晶化前后的复合材料的热分解行为作了实验对比和理论分析。     

Ni-Cr-P三元合金化学镀层的组织结构

用ＳＥＭ ，ＴＥＭ ，ＤＴＡ，ＸＲＤ 等方法研究了化学镀Ｎｉ－Ｃｒ－Ｐ 三元合金镀层的形貌和结构变化。结果表明，镀层组成均匀，呈非晶态结构，初始晶化温度为２７０．７ ℃，热处理可使镀层析出晶态Ｎｉ相和 Ｎｉ３Ｐ 相，高温热处理条件下还有晶态Ｃｒ 相和 Ｃｒ３Ｐ 相析出。     

纳米晶Ba1—xPbxTiO3的合成与表征

以醋酸铅，硬脂酸钡和钛酸丁酯为原料，用硬脂酸凝胶法（ＳＡＧ）合成了粒度均匀，粒径１０－２０ｎｍ的Ｂａ１－ｘＰｂｘＴｉＯ３纳米晶粉末，利用红外光谱（ＩＲ），热重（ＴＧ）和差热分析（ＤＴＡ）研究了纳米晶粉末的合成过程。用ＴＥＭ，ＸＲＤ观察和研究纳米晶的形貌及晶体结构，并用发射光谱测定样品的纯度。     

ZnFe2O4纳米晶的性能

用ＰＥＧ凝胶法合成出不同平均粒径的ＺｎＦｅ２Ｏ４纳米晶。用ＴＥＭ和ＸＲＤ分析其结构、粒径和形貌。用磁天平仪和红外光谱仪（ＩＲ）等手段研究其性能。结果表明ＺｎＦｅ２Ｏ４纳米晶在室温下有磁性，表面不饱和离子配位数降低。     

纳米晶Ba_（1－x）Pb_xTiO_3的合成与表征

以醋酸铅、硬脂酸钡和钛酸丁酯为原料，用硬脂酸凝胶法（ＳＡＧ）合成了粒度均匀、粒径１０－２０ｎｍ的Ｂａ（１－ｘ）ＰｂｘＴｉＯ３纳米晶粉末．利用红外光谱（ＩＲ）、热重（ＴＧ）和差热分析（ＤＴＡ）研究了纳米晶粉末的合成过程．用ＴＥＭ、ＸＲＤ观察和研究纳米晶的形貌及晶体结构，并用发射光谱测定样品的纯度．     

Al(PO_3)_3-NaBF_4-AlF3 系统玻璃的分相及晶化的研究

本工作利用 DTA、RTEM、X 射线及 IR 技术研究了 Al(PO_3)_s-NaBF_4-AlF_3系统玻璃的分相机理及分相与晶化之间的关系。从实验结果得出,分相玻璃的 DTA 曲线上存在有两个明显的 T_g 温度。其中,高 T_g 相为富磷氧相,低T_g 相为贫磷氧相。且分相玻璃的第二相呈粒子形态,属成核生长机理。粒子长大服从扩散机制。该系统玻璃分相导致整体析晶。高磷区析晶相为 Al(PO_3)_3,低磷区析晶相为 NaAlP_2O_7。     

A study of the LiYF4-LiErF4 psuedo-binary system

The constitution and structure of compounds represented by the general formula LiY_1–x Er _x F₄ (0 < x < 1) have been studied by X-ray diffraction, magnetic susceptibility and differential thermal analysis (DTA). X-ray diffraction shows that the bct Scheelite structure is retained across the system with only a very slight change in the lattice parameters. Large changes in room temperature magnetic susceptibilities as a function of x have been observed and these have been used to provide a very sensitive composition check on the compounds. DTA profile analysis shows that, for samples prepared in a carefully purified environment, the solidus-liquidus separation is so small that an approximation to congruent melting can be made for all the compounds in the system. A comparison with material prepared under unpurified conditions provides information on the effects of contamination upon the melting behaviour.     

含ZrF4氟铝酸盐玻璃研究

以10MgF_2-20CaF_2-10SrF_2-10BaF_2-15YF_3-35AlF_3(摩尔百分数)氟铝酸盐玻璃为基本组成,在玻璃中引入不同含量的ZrF_4,同时对其它组成进行适当调整,制得了厚度8mm无可见析晶的氟化物玻璃。利用差热分析(DTA)技术研究了ZrF_4对玻璃形成能力和玻璃析晶动力学的影响,结果表明,少量的ZrF_4可以提高玻璃的抗失透能力,过量的ZrF_4会降低玻璃形成能力;ZrF_4的最佳含量范围为7.3～11.4mol％。根据测得的玻璃的红外透过光谱显示,该玻璃具有良好的透红外光性能。     

Structural relaxation and embrittlement of Fe74Co10B16 and Fe74Co5Cr5B16 metallic glasses

Structural relaxation and annealing embrittlement behaviour of Fe₇₄Co₁₀B₁₆ and Fe₇₄Co₅Cr₅B₁₆ metallic glasses has been studied by differential scanning calorimetry (DSC) and bend ductility measurements. A pre-anneal technique was employed with DSC to determine activation energies of relaxation at various temperatures. Activation energies of embrittlement were derived from measurements of the embrittlement kinetics. The results obtained for both the alloys are compared to ascertain the effects of chromium addition. A spectrum of activation energies is obtained corresponding to structural relaxation and embrittlement. The activation energies of structural relaxation are found to be slightly higher for the chromium-containing alloy than for the ternary alloy. This observation is consistent with the higher crystallization temperature of the chromium-containing alloy as reported earlier. The ductile-brittle transition temperature of the Fe₇₄Co₁₀B₁₆ glass, however, decreases by 50 K (for 15 min anneal) on addition of 5 at% chromium. Activation energies for embrittlement of the chromium-containing alloy are also considerably smaller than for the ternary alloy. It is concluded that despite increasing the thermal stability, chromium reduces the mechanical stability of Fe₇₄Co₁₀B₁₆ glass.     

Effect of addition of chloride on the crystallization behaviour of fluoride glasses in ZrF4-BaF2-CsF system

Fluoride glasses based on ZrF₄-BaF₂-CsF doped with BaCl₂ up to 10 mol% have been prepared. Crystallization behaviour of these glasses has been investigated by means of DTA and XRD. Addition of 5 mol% BaCl₂ into the fluoride glass of the ZrF₄-BaF₂-CsF system enhances the glass forming ability and the thermal stability against crystallization, but the glass forming ability is decreased for glass containing 10 mol % of BaCl₂. The results have been discussed from the view point of thermodynamics and the dynamics of glass formation.     

Structure of oxide nanoparticles in Fe-16Cr MA/ODS ferritic steel

Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y₄Al₂O₉ (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 °C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.     

Structure and crystallization behavior of borate-based bioactive glass

The structure and crystallization behavior of borate-based bioactive glass, designated 45S5B1, were investigated by Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). FTIR spectroscopy revealed that the network structure of the glass consisted mainly of [BO₃], [BO₄] and [PO₄] units. Two distinct crystallization peaks were observed for this glass by DTA, with activation energies of 475 and 210 kJ/mol, respectively. XRD indicated that the crystallization process with higher activation was associated with the formation of CaNa₃B₅O₁₀, whereas the process with the lower activation energy was associated with the formation of CaB₂O₄. The results indicated that the crystallization process in 45S5B1 glass was dominated by bulk crystallization, although surface crystallization also occurred for small particle sizes (<50 μm).     

Thermal stability of the Fe80−xVxB20 metallic glasses as studied by the EEE and DTA methods

The surface and volume crystallization of Fe_80–xV_xB₂₀ (x=6, 10, 20) metallic glasses, produced by the melt spinning method, have been investigated by means of exoelectron emission (EEE) and differential thermal analysis (DTA). A comparison of the results of the EEE and DTA measurements shows clearly that surface crystallization occurs at temperatures 200 K lower than volume crystallization. The activation energy for the surface crystallization is also distinctly lower than that for crystallization in the bulk.Presented in part at the 4th International Conference on Physics of Magnetic Materials, Szczyrk-Bia, Poland, September 4–10, 1988. This work was financially supported by the Ministry of National Education within the Central Program of Fundamental Research CPBP 01.08.A.     

Combustion synthesis of inverse spinel LiNiVO4 nano-particles using gelatine as the new fuel

An inverse spinel type LiNiVO₄ nano-particles have been synthesized to be used as cathode active material for Li-ion batteries by adopting combustion method using gelatine as the new fuel, which act as an excellent combustion fuel as well as very good dispersing agent. The optimum temperature for the phase formation and/or complete crystallization of the precursor sample is found out by TG/DTA analysis. The structural property of the synthesized product is characterized by X-ray diffraction and FTIR spectroscopy studies. The morphology and the particle size of the synthesized powder is analyzed by TEM studies. The electrochemical reversibility and the charge/discharge studies of the synthesized LiNiVO₄ are examined by fabricating lithium-ion polymer cell in the configuration of C/LiNiVO₄ employing Li⁺ ion conducting PVdF-HFP based micro-porous polymer electrolyte.     

Influence of Annealing Conditions on Nanocrystalline and Ultra-Soft Magnetic Properties of Fe75.5Cu1Nb1Si13.5B9 Alloy

The magnetic and structural properties of FINEMET alloy with a composition of Fe75.5Cu1Nb1Si13.5B9 were investigated after primary and secondary crystallization of amorphous ribbon sample.The crystallization behavior and the nanocrystal formation of the samples were performed by differential thermal analysis(DTA) which in turn was supported by X-ray diffraction(XRD) study.Temperature dependence of initial permeability of amorphous and devitrified toroid shaped samples has been measured.Enhancement of Curie temperature of the amorphous alloy has been observed due to the irreversible structural relaxation.With the appearance of nanocrystalline phase the Curie temperature of the residual amorphous phase gradually decrease with the increase of annealing temperature.Their temperature dependence reflects the characteristic annealing temperature evolution of the basic magnetic parameters in these nanocrystalline systems.Saturation magnetization,Ms,increases with annealing temperature Ta for the samples and finally decreases during annealing at a temperature much higher than peak crystallization temperature.