公开(公告)号：US5523284A

公开(公告)日：1996-06-04

申请号：US315589

申请日：1994-09-30

申请人： James G. Fagan, Jr. ,  Vasantha R. W. Amarakoon

发明人： James G. Fagan, Jr. ,  Vasantha R. W. Amarakoon

IPC分类号： C04B35/45 ,  H01L39/24 ,  H01B12/00 ,  H01L39/12

CPC分类号： H01L39/2419 ,  C04B35/4508 ,  Y10S505/741 ,  Y10S505/742 ,  Y10S505/776 ,  Y10S505/777 ,  Y10S505/778 ,  Y10S505/779 ,  Y10S505/78 ,  Y10S505/782 ,  Y10S505/783 ,  Y10S505/784 ,  Y10S505/785

摘要： In accordance this invention, there is provided a process for making a bulk superconductive material. In the first step of this process, a diffusion couple is formed from superconductor oxide and impurity oxide. Thereafter, the diffusion couple is heated to a temperature in excess of 800 degrees Centigrade, cooled at a controlled rate, and annealed.

摘要翻译： 根据本发明，提供了制造体超导材料的方法。 在该工艺的第一步中，由超导体氧化物和杂质氧化物形成扩散耦合。 此后，将扩散耦合物加热至超过800摄氏度的温度，以受控的速率冷却并退火。

公开(公告)号：US4981633A

公开(公告)日：1991-01-01

申请号：US188306

申请日：1988-04-29

申请人： Aldo B. Alles ,  Vasantha R. W. Amarakoon ,  Vernon L. Burdick

发明人： Aldo B. Alles ,  Vasantha R. W. Amarakoon ,  Vernon L. Burdick

IPC分类号： C04B35/468 ,  C04B35/495 ,  H01C17/30

CPC分类号： H01C17/30 ,  C04B35/4682 ,  C04B35/495

摘要： A process for preparing a positive temperature coefficient thermistor is disclosed. This thermistor is comprised of at least about 60 weight percent of undoped, crystalline, ferroelectric material, and it has a room-temperature resistivity of less than 5,000 ohm-centimeters, an undegraded resistivity of at least about 1,000,000 ohm-centimeters, a degraded resistivity of at least about 900,000 ohm-centimeters, a ratio between its undegraded resistivity and its room-temperature resistivity of at least about 1,000, and a ratio between its undegraded resistivity and its degraded resistivity not exceeding 2.0.The process of this invention is comprised of the steps of sequentially: (1) providing a powder composition comprised of at least about 60 weight percent of undoped, crystalline, ferroelectric material; (2) fabricating the powder composition into a shaped powder compact; (3) sintering said powder compact by subjecting it to a temperature of from about 1150 to about 1450 degrees centigrade for at least about 1 hour, thereby forming a consolidated, sintered body; (4) reducing said sintered body by subjecting it to a temperature of from about 700 to about 1,400 degrees centigrade for at least about 30 minutes while maintaining said sintered body under a reducing atmosphere comprised of hydrogen; and (5) halogenating said reduced, sintered body by subjecting it to a source of halogen while maintaining it in a closed container at a temperature of from about 700 to about 1200 degrees centigrade for at least about 5 minutes.

摘要翻译： 公开了一种制备正温度系数热敏电阻的方法。 该热敏电阻由至少约60重量％的未掺杂，结晶的铁电材料组成，并且其具有小于5,000欧姆厘米的室温电阻率，至少约1,000,000欧姆厘米的未降解电阻率，劣化的电阻率 至少约900,000欧姆厘米，其未降解的电阻率与其室温电阻率之比至少约为1,000，其未降解的电阻率与其劣化的电阻率之比不超过2.0。 本发明的方法包括以下步骤：（1）提供由至少约60重量％的未掺杂的结晶的铁电材料组成的粉末组合物; （2）将粉末组合物制成成形粉末压块; （3）通过使其达到约1150至约1450摄氏度的温度至少约1小时来烧结所述粉末压块，从而形成固结的烧结体; （4）在将所述烧结体保持在由氢组成的还原气氛下，使所述烧结体经受约700至约1400摄氏度的温度至少约30分钟来还原所述烧结体; 和（5）通过使所述还原的烧结体在约700至约1200摄氏度的温度下将其保持在密闭的容器中至少约5分钟，将其经卤素源卤化。