YBCO的氧化还原反应及其电学性质
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摘要
本文研究了YBCO的氧化还原反应及其导电特性。用多个升温速率方法得到了YBCO的氧脱附活化能。实验测量了YBCO的电阻率随氧分压的变化关系。用Sol-gel及PMP等方法制备了YBCO厚膜，并研究了其对氧的检测灵敏度。
采用多升温速率热重法得到的TG、DTG数据计算YBa_2Cu_3O_(7-x)的氧脱附活化能。实验表明，当温度在500-800℃范围变化时，TG、DTG的变化行为及脱附活化能明显的和样品的氧含量有关。当样品为正交相时，脱附活化能随着温度的升高明显增加，而四方相时则变化比较平缓。
在400℃到850℃温度范围，研究了高温超导材料YBa_2Cu_3O_(7-x)块材的电阻率随环境氧分压的变化关系。实验表明YBa_2Cu_3O_(7-x)对氧有较强的选择性，当氧分压增大时(1Pa→1.01×10~5Pa)，块材样品的ρ(t)曲线出现瞬间陡降并迅速达到平衡值；但当氧分压减小时(1.01×10~5Pa→1Pa)，电阻率增加较慢，达到平衡所需的时间较长。
实验表明，采用Sol-gel方法制备的YBCO样品比其它方法制备的样品的致密度高。实验测量了YBCO厚膜在不同温度条件下对氧的检测灵敏度，发现YBCO厚膜的检测灵敏度随着温度的升高而增大，并且在650℃达到最大值62。同块材样品相比，实验证实YBCO厚膜样品的响应速度得到明显提高并具有较好的响应特性，有可能作为一种新的氧传感器材料。
Both redox reaction and electricity properties of YBa2Cu3O7-x were investigated. The oxygen desorption activation energy of YBaaCusO7-x was obtained by different heating rates and the relationship between resistivity of YBa2Cu3O7-x and oxygen pressure was measured. YBa2Cu3O7-x thick films were also prepared by Sol-gel and PMP methods and their sensitivity for oxygen was studied.
The measurement of oxygen desorption activation energy by thermogravimetry (TG) and differential thermogravimetry (DTG) curves with different heating rates shows clear evidences that the behavior of TG, DTG, and desorption activation energy have some relations with the oxygen stoichiometry of the specimeri when temperature changes from 500C to 800C. In the orthorhombic phase, the desorption activation energy has an obvious increase with the increase of temperature, while it varies smoothly in the tetragonal phase as the temperature increases.
The resistivity of the high temperature superconducting material YBa2Cu3O7_x as a function of oxygen pressure in the range of 400C-850C for bulk samples was studied. It shows mat YBa2Cu3O7.x has a strong selectivity for oxygen. The resistivity decreases very rapidly with the increasing of oxygen partial pressure and reaches its equilibrium value in a short time. When the oxygen partial pressure decreases, the resistivity of YBa2Cu3O7-x increases slowly and a quite long time is need to keep balance.
The sample prepared by Sol-gel way shows higher density than samples achieved by other ways. Measurement of thick film's sensitivity for oxygen in different temperature is also performed. It shows that the sensitivity to oxygen pressure increases with the increase of temperature and reaches a maximum value 62 at 650C. The experiments also show that the responding speed of the thick film is improved and it has better properties than bulk samples and the YBCO film may be as a new oxygen sensor material in practical application.
采用多升温速率热重法得到的TG、DTG数据计算YBa_2Cu_3O_(7-x)的氧脱附活化能。实验表明，当温度在500-800℃范围变化时，TG、DTG的变化行为及脱附活化能明显的和样品的氧含量有关。当样品为正交相时，脱附活化能随着温度的升高明显增加，而四方相时则变化比较平缓。
在400℃到850℃温度范围，研究了高温超导材料YBa_2Cu_3O_(7-x)块材的电阻率随环境氧分压的变化关系。实验表明YBa_2Cu_3O_(7-x)对氧有较强的选择性，当氧分压增大时(1Pa→1.01×10~5Pa)，块材样品的ρ(t)曲线出现瞬间陡降并迅速达到平衡值；但当氧分压减小时(1.01×10~5Pa→1Pa)，电阻率增加较慢，达到平衡所需的时间较长。
实验表明，采用Sol-gel方法制备的YBCO样品比其它方法制备的样品的致密度高。实验测量了YBCO厚膜在不同温度条件下对氧的检测灵敏度，发现YBCO厚膜的检测灵敏度随着温度的升高而增大，并且在650℃达到最大值62。同块材样品相比，实验证实YBCO厚膜样品的响应速度得到明显提高并具有较好的响应特性，有可能作为一种新的氧传感器材料。
Both redox reaction and electricity properties of YBa2Cu3O7-x were investigated. The oxygen desorption activation energy of YBaaCusO7-x was obtained by different heating rates and the relationship between resistivity of YBa2Cu3O7-x and oxygen pressure was measured. YBa2Cu3O7-x thick films were also prepared by Sol-gel and PMP methods and their sensitivity for oxygen was studied.
The measurement of oxygen desorption activation energy by thermogravimetry (TG) and differential thermogravimetry (DTG) curves with different heating rates shows clear evidences that the behavior of TG, DTG, and desorption activation energy have some relations with the oxygen stoichiometry of the specimeri when temperature changes from 500C to 800C. In the orthorhombic phase, the desorption activation energy has an obvious increase with the increase of temperature, while it varies smoothly in the tetragonal phase as the temperature increases.
The resistivity of the high temperature superconducting material YBa2Cu3O7_x as a function of oxygen pressure in the range of 400C-850C for bulk samples was studied. It shows mat YBa2Cu3O7.x has a strong selectivity for oxygen. The resistivity decreases very rapidly with the increasing of oxygen partial pressure and reaches its equilibrium value in a short time. When the oxygen partial pressure decreases, the resistivity of YBa2Cu3O7-x increases slowly and a quite long time is need to keep balance.
The sample prepared by Sol-gel way shows higher density than samples achieved by other ways. Measurement of thick film's sensitivity for oxygen in different temperature is also performed. It shows that the sensitivity to oxygen pressure increases with the increase of temperature and reaches a maximum value 62 at 650C. The experiments also show that the responding speed of the thick film is improved and it has better properties than bulk samples and the YBCO film may be as a new oxygen sensor material in practical application.
引文
1．吴德惠、王彩君编著，《传感器与信号处理》，北京电子工业出版社 1998
2. 宋国庆、刘红宇等，黑龙江电子技术 1999年3期
3．徐毓龙、姚奎等，《第二届全国敏感元件与传感器学术会议论文集》11， 521
（1991）上海。
4．金篆藏、王明时，《现代传感技术》，北京电子工业出版社，1995
5. 向锐、刘光葵等，传感器技术，1999年，第18卷3期。
6．张益康、杨博，传感器世界，1996年9期
7.刘志刚、张玉英等，传感技术学报，1997年3期。
8．河金田、苏运东等，《氧传感器原理与应用》，河南科学技术出版社， 1996
9．Gopel W, ocker G, Feierabend R, Phys. Rev.B,28(6),3427-3438(1983)
10. Valaso G, Schnell J P, Sensors Actuators,2，371（1982）
11．Takashi H, Kondo H Saji K． 4th conf chemical sensors, Japan 1985
12．Siebert E, Fouletier J. Proc 2nd Int Meet Chemical Sensors，France.1986
13．Seiter R E and Clark R J，Sensors and Actuators.13(1-3), 38（1993）
14．Kimer U Schierbaum K D, Gopel W.Sensors and Actuators，92，400－406（1990）
15．Ohtaki M，Peng J, Eguchi K,et al, Sensors and Actuators, 13-14,496-496(1993)
16. Hasegewa S，Sasaki Y, Matsuhara S， Sensors and Actuators， 13，509(1993)
17．Ishibashi K，Sensors and Actuators， 13－14，41（1993）
18．Zhu Zhili, Yang Delin, Yiqun Guo et al, Physica C, 383，169-174（2002）
19．杨德林、孟令启等，低温与超导， 29（1），48 （2001）
20．韩汝珊著，高温超导物理 北京大学出版社，1998
2. 宋国庆、刘红宇等，黑龙江电子技术 1999年3期
3．徐毓龙、姚奎等，《第二届全国敏感元件与传感器学术会议论文集》11， 521
（1991）上海。
4．金篆藏、王明时，《现代传感技术》，北京电子工业出版社，1995
5. 向锐、刘光葵等，传感器技术，1999年，第18卷3期。
6．张益康、杨博，传感器世界，1996年9期
7.刘志刚、张玉英等，传感技术学报，1997年3期。
8．河金田、苏运东等，《氧传感器原理与应用》，河南科学技术出版社， 1996
9．Gopel W, ocker G, Feierabend R, Phys. Rev.B,28(6),3427-3438(1983)
10. Valaso G, Schnell J P, Sensors Actuators,2，371（1982）
11．Takashi H, Kondo H Saji K． 4th conf chemical sensors, Japan 1985
12．Siebert E, Fouletier J. Proc 2nd Int Meet Chemical Sensors，France.1986
13．Seiter R E and Clark R J，Sensors and Actuators.13(1-3), 38（1993）
14．Kimer U Schierbaum K D, Gopel W.Sensors and Actuators，92，400－406（1990）
15．Ohtaki M，Peng J, Eguchi K,et al, Sensors and Actuators, 13-14,496-496(1993)
16. Hasegewa S，Sasaki Y, Matsuhara S， Sensors and Actuators， 13，509(1993)
17．Ishibashi K，Sensors and Actuators， 13－14，41（1993）
18．Zhu Zhili, Yang Delin, Yiqun Guo et al, Physica C, 383，169-174（2002）
19．杨德林、孟令启等，低温与超导， 29（1），48 （2001）
20．韩汝珊著，高温超导物理 北京大学出版社，1998