The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
J.m. Williams - One of the best experts on this subject based on the ideXlab platform.
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an automated cryogenic current comparator Resistance Ratio bridge for routine Resistance measurements
Metrologia, 2010Co-Authors: J.m. Williams, T.j.b.m. Janssen, G Rietveld, E HoutzagerAbstract:A design of an automated cryogenic current comparator (CCC) Resistance Ratio bridge for routine measurements in a national metrology institute or standards laboratory is described. It employs a type II CCC for use in a low loss liquid helium storage vessel and can be continuously operated from the mains power via specialized isolated supplies. All parameters including the servo control loops are digitally controlled. Noise sources in the system are analysed using the Allan deviation and it is demonstrated that non-white noise sources can be eliminated by choosing an appropriate current reversal rate.
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Cryogenic current comparator bridge for quantum Hall Resistance Ratio measurements
IEE Proceedings - Science Measurement and Technology, 2002Co-Authors: P. Kleinschmidt, J.m. Williams, N.e. Fletcher, T.j.b.m. JanssenAbstract:A cryogenic current comparator (CCC) bridge for quantum Hall Resistance Ratio measurement has been constructed. Compared to previous CCC systems at the National Physical Laboratory, UK, the new system differs in two aspects. Firstly, it uses a type-II CCC, i.e. the Ratio windings are on the outside and the detection winding is on the inside. This has the advantage that the CCC can be made very compact and fits into a standard storage Dewar. Secondly, the bridge electronics uses a digital servo and the SQUID feedback loop is disabled during current reversals. The overall relative measurement uncertainty of the system is of the order of 10/sup -9/.
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An automated cryogenic current comparator Resistance Ratio bridge
Conference on Precision Electromagnetic Measurements, 1990Co-Authors: J.m. Williams, A. HartlandAbstract:The method of measurement of two-terminal cryogenic and four-terminal room-temperature resistors using a DC cryogenic current comparator bridge is well established. A bridge which is based on this technique and is fully automated with a computer controlling both the measurement current and the readings of the bridge imbalance current is described. The bridge is designed to measure integer Ratios of 1:1 to 1:25 of four-terminal room-temperature resistors in the range 1 Omega to 10 k Omega . An overall accuracy of 1 part in 10/sup 9/ for differences in the Ratio from nominal of up to 100 p.p.m. is desired. Some initial determinations of the resolution have been made for a measurement of 10 Omega :100 Omega . These determinations were carried out without the balance servo, and the output from the null detector was measured with a digital voltmeter connected to the computer. An analysis of a set of 11 reversals gave a standard deviation for a single reversal of 1 part in 10/sup 8/ and therefore a standard error of the mean of 3 parts in 10/sup 9/.
Y. Jiang - One of the best experts on this subject based on the ideXlab platform.
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High Resistance Ratio of bipolar resistive switching in a multiferroic/high-K Bi(Fe 0.95 Cr 0.05 )O 3 /ZrO 2 /Pt heterostructure
Applied Surface Science, 2018Co-Authors: Bo-wen Dong, Jun Miao, F. Shao, Jingmei Yuan, K.k. Meng, Yidong Wu, X.g. Xu, Y. JiangAbstract:Abstract An novel heterostructure composed of multiferroic Bi(Fe0.95Cr0.05)O3 (BFCO) and high-K ZrO2 (ZO) layers is investigated. Ferroelectric and electrical properties of the BFZO/ZO heterostructure have been investigated. A pronounced bipolar ferroelectric resistive switching characteristic was achieved in the heterostructure at room temperature. Interestingly, the BFCO/ZO structures exhibit a reproducible resistive switching with a high On/Off Resistance Ratio ∼2×103 and long retention time. The relationship between polarization and band structure at the interface of BFCO/ZO bilayer under the positive and negative sweepings has been discussed. As a result, the BFCO/ZO multiferroic/high-K heterostructure with high On/Off Resistance Ratio and long retention characterizes, exhibits a potential in future nonvolatile memory application.
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high Resistance Ratio of bipolar resistive switching in a multiferroic high k bi fe 0 95 cr 0 05 o 3 zro 2 pt heterostructure
Applied Surface Science, 2018Co-Authors: Bo-wen Dong, Jun Miao, F. Shao, Jingmei Yuan, K.k. Meng, Yidong Wu, X.g. Xu, Y. JiangAbstract:Abstract An novel heterostructure composed of multiferroic Bi(Fe0.95Cr0.05)O3 (BFCO) and high-K ZrO2 (ZO) layers is investigated. Ferroelectric and electrical properties of the BFZO/ZO heterostructure have been investigated. A pronounced bipolar ferroelectric resistive switching characteristic was achieved in the heterostructure at room temperature. Interestingly, the BFCO/ZO structures exhibit a reproducible resistive switching with a high On/Off Resistance Ratio ∼2×103 and long retention time. The relationship between polarization and band structure at the interface of BFCO/ZO bilayer under the positive and negative sweepings has been discussed. As a result, the BFCO/ZO multiferroic/high-K heterostructure with high On/Off Resistance Ratio and long retention characterizes, exhibits a potential in future nonvolatile memory application.
Teruo Matsushita - One of the best experts on this subject based on the ideXlab platform.
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Residual Resistance Ratio Measurement Method of Cu/Nb3Sn Composite Conductors
Advances in Superconductivity XII, 2020Co-Authors: Satoru Murase, Teruo Matsushita, Takashi Saitoh, Rikuo Ogawa, H. Moriai, Kozo OsamuraAbstract:To submit residual Resistance Ratio (RRR) measurement method of Cu/Nb3Sn composite conductor as one of new work items to IEC-TC90 in the near future, inter-comparison tests have been carried out. Four laboratories joined the tests using the bronze-processed Cu/Nb3Sn with the external stabilizer as a sample. Laboratory W reacted and measured samples A, B and C, then they were distributed to the other three laboratories (X, Y and Z). Laboratories X, Y and Z measured samples A, B and C, respectively and those data were compared with those of W. As a result, coefficient of variation, COV, of RRR values of 6.7% was obtained. Thermoelectric voltages were also measured in the tests and it was found that it did not affect scattering of RRR measurement if we changed the polarity. If allowable target precision is extended up to around 10%, we will reach the goal of the standardization in RRR measurement method of Cu/Nb3Sn in a year.
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Round Robin Test of Residual Resistance Ratio of Nb3Sn Composite Superconductors
IEEE Transactions on Applied Superconductivity, 2018Co-Authors: Teruo Matsushita, Edmund S. Otabe, Taejong Hwang, Daniele Turrioni, L.d. Cooley, Mark J. RaineAbstract:A round robin test of residual Resistance Ratio (RRR) was performed for Nb 3Sn composite superconductors prepared by internal tin method by six institutes with the international standard test method described in IEC 61788-4. It was found that uncertainty mainly resulted from determination of the cryogenic Resistance from the intersection of two straight lines drawn to fit the voltage vs. temperature curve around the resistive transition. As a result, the measurement clarified that RRR can be measured with expanded uncertainty not larger than 5% with the coverage factor 2 by using this test method.
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Round Robin Test of Residual Resistance Ratio of Nb3Sn Composite Superconductors
IEEE Transactions on Applied Superconductivity, 2018Co-Authors: Teruo Matsushita, Edmund S. Otabe, Taejong Hwang, Lance Cooley, Daniele Turrioni, Mark J. Raine, Damian P. HampshireAbstract:In this paper, a round robin test of residual Resistance Ratio (RRR) is performed for Nb3Sn composite superconductors prepared by an internal tin method by six institutes with the international standard test method described in IEC 61788-4. It was found that uncertainty mainly resulted from determination of the cryogenic Resistance from the intersection of two straight lines drawn to fit the voltage versus temperature curve around the resistive transition. The measurement clarified that RRR can be measured with expanded uncertainty not larger than 5% with the coverage factor 2 by using this test method.
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Inter-Comparison Test Results for Residual Resistance Ratio of Cu/Nb3Sn Composite Conductors
Advances in Superconductivity XI, 1999Co-Authors: Satoru Murase, Teruo Matsushita, Takashi Saitoh, H. Moriai, Kozo OsamuraAbstract:The residual Resistance Ratio (RRR) measurement method for Cu/Nb3Sn was selected to be one of the next new work proposal items for submission to IEC-TC90 in the near future. Inter-comparison tests have been carried out for some years in Japan and show that the RRR of Cu/Nb3Sn for the external Cu type is very sensitive to heat-treatment conditions and has large scattering. On the other hand, a relatively low scattering factor of under 9% was obtained in the test in which the scattering problems at heat-treatment were removed. If pre-reacted Cu/Nb3Sn is treated, the goal of the standardization in RRR measurement method will be attained before long.
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Results of Round Robin Test of Residual Resistance Ratio in Cu/Nb-Ti Composite Superconductor
Advances in Superconductivity XI, 1999Co-Authors: Teruo Matsushita, Edmund S. Otabe, Satoru Murase, Kozo OsamuraAbstract:An international round robin test of the residual Resistance Ratio (RRR) measurement was carried out on a Cu/Nb-Ti composite superconductor following a Working Draft for the test method prepared by Working Group 4 in IEC/TC90. Thirteen institutes from five countries participated in the round robbin test. The effect of the bending strain on the Resistance at cryogenic temperatures was corrected using an empirical formula. The average and the standard deviation of RRR were 178.5 and 4.4, respectively. As a result the coefficient of variation (COV) was 2.44 %. Since the target of COV is 5 %, it is concluded that RRR can be correctly measured following the method in the Working Draft.
E Houtzager - One of the best experts on this subject based on the ideXlab platform.
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an automated cryogenic current comparator Resistance Ratio bridge for routine Resistance measurements
Metrologia, 2010Co-Authors: J.m. Williams, T.j.b.m. Janssen, G Rietveld, E HoutzagerAbstract:A design of an automated cryogenic current comparator (CCC) Resistance Ratio bridge for routine measurements in a national metrology institute or standards laboratory is described. It employs a type II CCC for use in a low loss liquid helium storage vessel and can be continuously operated from the mains power via specialized isolated supplies. All parameters including the servo control loops are digitally controlled. Noise sources in the system are analysed using the Allan deviation and it is demonstrated that non-white noise sources can be eliminated by choosing an appropriate current reversal rate.
Bo-wen Dong - One of the best experts on this subject based on the ideXlab platform.
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High Resistance Ratio of bipolar resistive switching in a multiferroic/high-K Bi(Fe 0.95 Cr 0.05 )O 3 /ZrO 2 /Pt heterostructure
Applied Surface Science, 2018Co-Authors: Bo-wen Dong, Jun Miao, F. Shao, Jingmei Yuan, K.k. Meng, Yidong Wu, X.g. Xu, Y. JiangAbstract:Abstract An novel heterostructure composed of multiferroic Bi(Fe0.95Cr0.05)O3 (BFCO) and high-K ZrO2 (ZO) layers is investigated. Ferroelectric and electrical properties of the BFZO/ZO heterostructure have been investigated. A pronounced bipolar ferroelectric resistive switching characteristic was achieved in the heterostructure at room temperature. Interestingly, the BFCO/ZO structures exhibit a reproducible resistive switching with a high On/Off Resistance Ratio ∼2×103 and long retention time. The relationship between polarization and band structure at the interface of BFCO/ZO bilayer under the positive and negative sweepings has been discussed. As a result, the BFCO/ZO multiferroic/high-K heterostructure with high On/Off Resistance Ratio and long retention characterizes, exhibits a potential in future nonvolatile memory application.
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high Resistance Ratio of bipolar resistive switching in a multiferroic high k bi fe 0 95 cr 0 05 o 3 zro 2 pt heterostructure
Applied Surface Science, 2018Co-Authors: Bo-wen Dong, Jun Miao, F. Shao, Jingmei Yuan, K.k. Meng, Yidong Wu, X.g. Xu, Y. JiangAbstract:Abstract An novel heterostructure composed of multiferroic Bi(Fe0.95Cr0.05)O3 (BFCO) and high-K ZrO2 (ZO) layers is investigated. Ferroelectric and electrical properties of the BFZO/ZO heterostructure have been investigated. A pronounced bipolar ferroelectric resistive switching characteristic was achieved in the heterostructure at room temperature. Interestingly, the BFCO/ZO structures exhibit a reproducible resistive switching with a high On/Off Resistance Ratio ∼2×103 and long retention time. The relationship between polarization and band structure at the interface of BFCO/ZO bilayer under the positive and negative sweepings has been discussed. As a result, the BFCO/ZO multiferroic/high-K heterostructure with high On/Off Resistance Ratio and long retention characterizes, exhibits a potential in future nonvolatile memory application.
