| 摘要 |
PROBLEM TO BE SOLVED: To provide a whisker crystal of iron-based superconductor which exhibits superconductivity at an absolute temperature of about 30 K, and to provide a production method which is easy to cope with toxicity and can industrially advantageously produce the whisker crystal.SOLUTION: A mixed powder comprising raw materials constituted of a metal arsenide powder and a metal powder and an additive for promoting crystal growth is filled in a capsule-shaped reaction vessel made of metal. Then, a pressure of 240-380 MPa is mechanically applied via two punches arranged oppositely to each other. After depressurizing, the temperature of the reaction vessel is kept within the range of 700-1,000°C for ≥48 h. Successively, the reaction vessel is furnace cooled to 700°C or less at a fixed temperature lowering rate of ≤0.3°C/min. |
