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The defense date of the thesis is 2004-06-18
The current date is 2018-06-23
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URN etd-0618104-135527 Statistics This thesis had been viewed 1790 times. Download 9 times. Author Chia-Ying Tsai Author's Email Address No Public. Department Materials Engineering Year 2003 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 87 Title Preparation of NTC Ceramics Powder
by the Chemical Coprecipitation
Keyword Thermistor spinel Chemical Coprecipitation Chemical Coprecipitation spinel Thermistor Abstract Abstract
Have (Mn,Ni)3O4 oxide ceramics of spinelle structure. Its resistance will drop rapidly as temperature rises, this characteristic is applied the nagative temperature coefficience thermistors. It is to directly compound for the initial material by the oxides of Mn and Ni to prepare powder traditionally. The method is inexpensive and process easily, these are its advantage. But there are its shortcomings, for example: often happen problematic such as NiO that remains, composition is uneven, impurity of the powder and Stability of NTC,etc. So if will improve above-mentioned problems. Must require the purity of the powder, make very smallly and distributed homogeneous powder, the chemical coprecipitation will be a kind of very good method. The experiment is to regard nitrate as the initial material by chemical coprecipitation. The nitrate and ammonium oxalate was prepared 0.2M, and mixed and heated to produce powder. Find from experiment, can reduce calcining temperature about 200℃, it is simpler and easy to make than other method. The coprecipitation have seom advantage: (1) The powder particle is smaller about (80nm∼568nm). (2) Reduce the calcin temperature about 200℃ than solid-solid reaction method. (3) The composition is distributed evenly and had not NiO remains.
Advisor Committee Hur-Lon Lin - advisor
Chih-Wen Hsieh - co-chair
Wan-Yi Wei - co-chair
Files Date of Defense 2004-05-24 Date of Submission 2004-06-18