| 摘要 |
PURPOSE:To obtain a calcinator, especially equipped with a controlling means for O2 partial pressure near a material to be calcined in a calcining furnace body and capable of controlling a calcining atmosphere according to respective steps of calcination and improving superconductive characteristics of superconducting material compositions. CONSTITUTION:The interior of a calcining furnace 1 is evacuated to a prescribed vacuum degree with a gas discharge system 2 and a mixed gas of O2 and N2 is fed into the interior of the furnace 1. That is the O2 is introduced from a gas cylinder (3A) into a gas mixer 5 and the N2 is introduced from a gas cylinder (4A) thereinto, mixed and then introduced into the furnace 1. In this case, the quantity of O2 near a material to be calcined is sensed with an oxygen sensor 7 provided in the vicinity of the material to be calcined in the furnace 1. The above-mentioned sensed signal is then inputted to an oxygen densitometer 8 and the O2 concentration signal is further inputted to an oxygen partial pressure controller 9. On the other hand, O2 partial pressure previously memorized in a temperature controller 10 of the furnace 1 is compared with the O2 concentration signal from the densitometer 8 in the controller 9 to control opening and closing of control valves (3F) and (4F) so as to provide a prescribed value of the O2 partial pressure near the material to be calcined. Thereby, an oxide superconductor containing, e.g. Ag2O added to LaBa2Cu3O7-delta, is produced by using the above-mentioned calcinator. |
