巻号一覧
6 巻 (1959)
- 6 号 p. 213-
- 5 号 p. 181-
- 4 号 p. 149-
- 3 号 p. 91-
- 2 号 p. 45-
- 1 号 p. 1-
6 巻, 5 号
選択された号の論文の3件中1～3を表示しています
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OP磁石を生成する固相反応中村 弘, 河合 登1959 年 6 巻 5 号 p. 181-184
発行日: 1959/10/10
公開日: 2010/07/12
ジャーナル フリーOP magnet is industrially manufactured by nitric acid method. That is, the mixture of nitrate solutions of Fe and Co is prefired up to 850°C in air after evaporation and drying. The resulting powder is then pressed (compacted) to desired shape and fired above 1000°C in air of about 1mm Hg.
The chief constituents of the prefired powder are CoFe2O4 and a-Fe2O3, while the fired magnet consists of a solid solution CoFe2O4-Fe2O4 of spinel structure, the composition being approximately CO0.75-Fe2.25O4. Hence, the main reaction during firing-reaction of magnet formation-was considered to be
6 CoFe2O4+3 Fe2O3→8 Co0.75Fe2.25O4+1/2O2.
Authors studied about the reaction by assuming that the reaction velocity is controlled mainly by the diffusion velocity of Fe and Co ions in the solid solution, and that evolution of oxygen has no great influence upon the reaction velocity, and found that the so-called Jander's equation holds good in this case. The activation energy of the reaction was calculated to be 41Kcal/mol.抄録全体を表示PDF形式でダウンロード (310K) -
深津 保, 鈴木 謙爾1959 年 6 巻 5 号 p. 185-190
発行日: 1959/10/10
公開日: 2009/12/04
ジャーナル フリーFor the purpose of pre-paring Co-Ni alloy powder, the solid solution of hydroxides of Co and Ni, Co1-xNix (OH)2, were prepared by simultaneous-precipitation from mixture of aqueous solution of Co(NO3)2⋅6H2O and Ni(NO3)2⋅6H2O with 0.1N-NH4OH at 85°C and then these precipitates were reduced in hydrogen at various temperatures ranging from 300°C to 700°C. Analysis of crystal structure by X-ray and electron diffraction and chemical analysis of polarograph showed that the precipitates were solid solution of Co(OH)2 and Ni(OH)2 and their composition also corresponded to the mixed ratio of the nitrates of Co and Ni. From thermomagnetic analysis, the alloy powders reduced were homogeneous solid solution of Co and Ni with composition corresponded to the raw materials respectively. Observation of morphological properties of these powders by electron microscope showed that alloy powders consisted of the smallest unit particles which were linked up with each other, resulting formation of aggregates resembled in shape with original crystals of their mother salts. The size of the unit particles increased with increasing temperature of reduction. Metal-lographical phases of alloy powders prepared were obeerved by X-ray diffraction.抄録全体を表示PDF形式でダウンロード (4820K) -
高木 秀夫, 槌田 劭1959 年 6 巻 5 号 p. 191-195
発行日: 1959/10/10
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (352K)
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