AH電容橋低溫應(yīng)用

1、AH電容橋在低溫下的應(yīng)用1應(yīng)用方向在超低溫環(huán)境下測(cè)量材料的C-V特性在超低溫的情況下，使超低溫系統(tǒng)的穩(wěn)定性更高 固、液、氣態(tài)3He，4He 性質(zhì)的研究2一、超低溫環(huán)境下測(cè)量材料的C-V特性稀釋制冷機(jī) 9mK，10mK，12mK，17mK（稀釋制冷機(jī)利用He在He中稀釋能降溫的原理來(lái)制冷）3He低溫恒溫器 280mK絕熱退磁制冷機(jī) 50mK（絕熱去磁制冷機(jī)是利用順磁物質(zhì)在絕熱情況下去磁后溫度降低這一原理 ）（牛津公司 Janis低溫公司）3研究目的磁場(chǎng)變化與C的關(guān)系溫度變化與C關(guān)系光強(qiáng)度變化與C關(guān)系4樣品：碳納米管，硅納米線，納米器件連接方式：金線，探針，DIP器件樣品托: 絕緣、屏蔽設(shè)計(jì)樣品桿

2、：屏蔽設(shè)計(jì)（真空樣品桿，引線雙絞纏繞）5二、超低溫的情況下，使超溫系統(tǒng)的穩(wěn)定性更高 電容型溫度傳感器的應(yīng)用1.傳統(tǒng)溫度傳感器Si： 不能用于磁場(chǎng)環(huán)境RuO GaAlAs： （RuO-600在80mK時(shí)8Tesla的磁場(chǎng)可引入8的磁阻變化，從而導(dǎo)致7mK的溫度誤差 ）Cernox： 5 mK 1.4 K62.電容型溫度傳感器0.1mK 0.3K1mK 1K from： Large Magneto-Thermal Effect and The Spin-Phonon Coupling In A Parent Insulating Cuprate Pr1.3La0.7CuO4”, X. F. Sun

3、, I. Tsukada, T. Suzuki, Seiki Komiya, Yoichi Ando; arXiv:cond-mat/0502603, V2, July 27, 2005 7電容溫度傳感器測(cè)量設(shè)備上的應(yīng)用 （1）Faraday 磁強(qiáng)計(jì)上的應(yīng)用： 應(yīng)用于100mK，9T 電容型溫度傳感器，對(duì)磁性場(chǎng)不敏感。傳統(tǒng)溫度傳感器硅二極管，RuO，甚至Cernox傳感器都屬于電阻型傳感器，受磁場(chǎng)影響大.（2）SQUID超導(dǎo)量子磁強(qiáng)計(jì)上的應(yīng)用8應(yīng)用-低溫磁強(qiáng)計(jì)對(duì)磁場(chǎng)不敏感，電容測(cè)量用來(lái)校準(zhǔn)或更正背景效果法拉第磁強(qiáng)計(jì)：利用磁場(chǎng)引起介質(zhì)折射率變化而產(chǎn)生的旋光現(xiàn)象而制成，可測(cè)量脈沖強(qiáng)磁場(chǎng)、交變強(qiáng)磁場(chǎng)

4、。9三、固、液、氣態(tài)3He，4He 性質(zhì)的研究3He晶體在低于1mK時(shí)的形態(tài)和生長(zhǎng)動(dòng)力學(xué)的研究固態(tài)3He的熱力學(xué)測(cè)量超流態(tài)4He中，研究晶體的臨界速度氫自旋極化平衡狀態(tài)4He超流態(tài)的渦旋氣壓變化-d變化-C變化10The AH2500A was also used in “Pressure Measurements With A Precision of 0.001 Ppm In Magnetic Fields At Low Temperatures”, Y. Miura, N. Matsushima, T. Ando, S. Kono, S. Inoue, K. Ito, T. Mamiya

5、; Review of Scientific Instruments, Volume 64, Issue 11, November 1993, pp. 3215-3218.A Straty-Adams type strain gauge in a cell monitored 3He pressure In “Morphology and Growth Kinetics of 3He Crystals Below 1 mK”, V. Tsepelin, H. Alles, A. Babkin, R. Jochemsen, A. Ya, Oarshin, I. Todoshchenko and

6、G. Tvalashvili, in TKK Report 2001, ISBN - 951-22-5441-7, where the resolution of the pressure gauge, as measured with a AH2500A capacitance bridge, was a few bar at 35 bars. The AH2500A bridge provided an accuracy of a few K with 0.1 V excitation in work done at the University of Florida, Physics D

7、epartment / National High Field Magnetic Laboratory as noted by J. S. Xia, V. Shvarts, E. D. Adams, in “3He Melting Pressure Reduction in High Magnetic Field at Ultra-Low Temperatures”, as noted in the 1999 NHMFL Annual Research Review, pp. 194-195.Related to magnetic fields is the “Faraday Force Ma

8、gnetometer for High-Sensitivity Magnetization Measurements at Very Low Temperatures and High Fields”, Toshiro Sakakibara, Hiroyuki Mitamura, Takashi Tayama and Hiroshi Amitsuka, Japanese Journal of Applied Physics, Volume 33, September 15, 1994, pp. 5067-5072. Magnetic moment was measured with a res

9、olution of better than 1x10-7Am2 (1x10-4 emu). An AH2500A bridge measured the capacitance change of a parallel-plate variable capacitor.“”, Viktor Tsepelin, Low Temperature Laboratory, Helsinki University of Technology, June 2001.“Magnetoelastic Stresses in Rare-Earth Thin Films and Superlattices”,

10、J. I. Arnaudas, M. Ciria, C. de la Fuente, L. 11Benito, A. del Moral, R. C. C. Ward, M. R. Wells, C. Dufour, K. Dumesnil, A. Mougin; Low Temperature Physics, Volume 27, Issue 4, April 2001, pp. 249-265.“Very-Low-Temperature Capacitance Sensors”, M. Barucci, E. Olivieri, E. Pasca, L. Risegari, G. Ven

11、tura, A. Giuliani, G. Jug, M. Pedretti; TEMPMEKO 2004, Dubrovnik, Croatia, June 22-25, 2004.“Large Magneto-Thermal Effect and The Spin-Phonon Coupling In A Parent Insulating Cuprate Pr1.3La0.7CuO4”, X. F. Sun, I. Tsukada, T. Suzuki, Seiki Komiya, Yoichi Ando; arXiv:cond-mat/0502603, V2, July 27, 200

12、5.“Capacitance Thermometer For Use At Low Temperatures and High Magnetic Fields”, T. P. Murphy, E. C. Palm, L. Peabody, S. W. Tozer; Review of Scientific Instruments, Volume 72, Issue 8, August 2001, pp. 3462-3466. “Absence of Low Temperature Anomaly On The Melting Curve of 4He”, I. A. Todoshchenko, H. Alles, H. J. Junes, A. Ya. Parshin, V. Tsepelin; /abs/cond-mat/0703743, V1, March 28, 2007.“On The Properties of Vacancies In Solid 4He As Studied By Pressure Measurements”, P. Remeijer, S. C. Steel, R. Jochemsen, G. Frossati, J. M. Goodkind; Fizika Nizkikh Temperatur, Volume 23, Nos.