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水熱法合成無稀土永磁材料的研究

時間:2019-06-01 20:06來源:畢業論文
檸檬酸鈉和氫氧化鈉是合成鈷的過程中很重要的兩個影響因素,檸檬酸鈉的濃度影響鈷合成的內部生長結構,而氫氧化鈉充當還原劑,將溶液中的鈷離子還原成鈷

摘要  磁性材料曾在人類文明史上具有重要的地位,促進了世界文化的交流和傳播。現代社會磁性材料更是廣泛應用于信息儲存、電機、醫療、磁分離等眾多的領域。 本文研究的是不含稀土元素的ConC 磁性材料體系,因為六方緊密堆積的Co 具有很強的硬磁性,以及非常大的各向異性。整個的實驗過程可以分為三個部分來闡述,首先,實驗研究了水熱法合成納米級的鈷的工藝條件。實驗得出合成納米鈷的各原料的最適比,再通過控制加熱時間和溫度來比較不同溫度、時間下,溶劑熱反應的不同所合成的納米鈷的性能的不同;其次,將納米級的鈷和碳納米管真空封裝后,放在電阻爐或者馬弗爐里進行熱處理,研究 ConC 納米顆粒的合成與磁性能的變化;最后,將碳納米管直接摻雜到鈷的水熱合成過程中, 研究添加量對合成過程和產物結構的影響。研究結果表明檸檬酸鈉和氫氧化鈉是合成鈷的過程中很重要的兩個影響因素,檸檬酸鈉的濃度影響鈷合成的內部生長結構,而氫氧化鈉充當還原劑,將溶液中的鈷離子還原成鈷。經過熱處理的納米鈷和碳納米管合成了ConC 粉體,此方法合成的 ConC 相是 Co、Co2C、Co3C、CoC8 的混合相,并且熱處理溫度的不同,合成樣品的磁性能也不同。在水熱法合成鈷的過程中直接添加碳納米管合成的ConC 粉體,相比未添加碳納米管的樣品,矯頑力和飽和磁化強度都變大了。   35881
畢業論文關鍵詞:水熱合成法;納米級鈷;碳納米管;熱處理;ConC 粉體 
Abstract  Magnetic material plays an important role in  the history of human civilization, which greatly promotes the communication and communication of world culture. Nowdays,the magnetic material is widely used in the field of information storage, motor, medical, magnetic separation etc. The paper is a study of ConC magnetic material system, which is not containing rare earth elements. Because Cobalt of hexagonal closed-packed has strong hard magnetic properties, and very large anisotropy. The whole process can be pided into three parts. Firstly, The experiment studies the technological conditions for nanometer cobalt by hydrothermal synthesis method. The results show that the optimum ratio of reaction raw materials, then controlling the heating time and temperature to compare the different properties of cob alt nanoparticles in different solvent thermal reaction. Secondly, after the nano cobalt and carbon nanotubes were vacuum packed, they were heat treated in the resistance furnace. This is mainly to study the synthesis and magnetic properties of ConC nanoparticles. Finally, in the experiment, the carbon nanotube is directly doped into the hydrothermal synthesis process of cobalt to study the amount of influence on the synthesis process and the resulting product structure. The results show that Sodium citrate and sodium hydroxide are two very important factors in the process of synthesis of cobalt. The concentration of sodium citrate affects the internal growth structure of cobalt synthesis. While sodium hydroxide acts as reducing agent, cobalt ions can be red uced to cobalt. ConC powders that were synthesized by heat treatment process of cobalt and carbon nanotubes. The ConC phase synthesized by this method is the mixed phase of Co, Co2C, Co3C and CoC8. And with the difference of heat treatment temperature, the magnetic properties of the sample are also different. Synthesis of ConC powders by direct addition of carbon nanotubes during hydrothermal synthesis process of cobalt. Compared with the sample without CNTs, the coercivity and saturation magnetization of the samples have been become larger. 
源¥自%六:維;論-文'網=www.aftnzs.live

Key Words:hydrothermal  synthesis;  nanometer cobalt;  carbon nanotubes; heat treatment; ConC powder  
目錄
1緒論.1
1.1引言.1
1.2磁性材料.1
1.2.1硬磁材料1 水熱法合成無稀土永磁材料的研究:http://www.aftnzs.live/cailiao/20190601/34060.html
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