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Wiedemann HTA, Ruloff S, Richter R, Zollitsch CW, Kay CWM. Towards high performance dielectric microwave resonators for X-band EPR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 354:107519. [PMID: 37541024 DOI: 10.1016/j.jmr.2023.107519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 08/06/2023]
Abstract
Microwave (MW) resonators in Electron Paramagnetic Resonance (EPR) spectroscopy concentrate the MW magnetic field (B1) at the sample and separate the MW electric field from the sample. There are numerous experimental methods in EPR spectroscopy which all impose different requirements on MW resonators (e.g. high or low quality factor, MW conversion, and B1-field homogeneity). Although commercial spectrometers offer standardized MW resonators for a broad application range, newly emerging and highly-specialized research fields push these spectrometers to or beyond their sensitivity limits. Optimizing the MW resonator offers one direct approach to improve the sensitivity. Here we present three low-cost optimization approaches for a commercially available X-band (9-10 GHz) MW resonator for three experimental purposes (continuous-wave (CW), transient and pulse EPR). We obtain enhanced MW conversion factors for all three optimized resonators and higher quality factors for two optimized resonators. The latter is important for CW and transient EPR. Furthermore, we fabricated a resonator which features an extended area of homogeneous B1-field and, hence, improved pulse EPR performance. Our results demonstrate that small changes to a commercial MW resonator can enhance its performance in general or for specific applications.
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Affiliation(s)
- Haakon T A Wiedemann
- Department of Chemistry, Saarland University, Saarbrücken 66123, Saarland, Germany.
| | - Stefan Ruloff
- Department of Chemistry, Saarland University, Saarbrücken 66123, Saarland, Germany
| | - Rudolf Richter
- Department of Chemistry, Saarland University, Saarbrücken 66123, Saarland, Germany
| | - Christoph W Zollitsch
- Department of Chemistry, Saarland University, Saarbrücken 66123, Saarland, Germany; London Centre of Nanotechnology, University College London, London WC1H 0AH, United Kingdom; Department of Physics & Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Christopher W M Kay
- Department of Chemistry, Saarland University, Saarbrücken 66123, Saarland, Germany; London Centre of Nanotechnology, University College London, London WC1H 0AH, United Kingdom
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2
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Dayan N, Artzi Y, Jbara M, Cristea D, Blank A. Pulsed Electron-Nuclear Double Resonance in the Fourier Regime. Chemphyschem 2022; 24:e202200624. [PMID: 36464644 DOI: 10.1002/cphc.202200624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/24/2022] [Accepted: 12/01/2022] [Indexed: 12/11/2022]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy provides atomic-level molecular structural information. However, in molecules containing unpaired electron spins, NMR signals are difficult to measure directly. In such cases, data is obtained using the electron-nuclear double resonance (ENDOR) method, where nuclei are detected through their interaction with nearby unpaired electron spins. Unfortunately, electron spins spread the ENDOR signals, which challenges current acquisition techniques, often resulting in low spectral resolution that provides limited structural details. Here, we show that by using miniature microwave resonators to detect a small number of electron spins, integrated with miniature NMR coils, one can excite and detect a wide bandwidth of ENDOR data in a single pulse. This facilitates the measurement of ENDOR spectra with narrow lines spread over a large frequency range at much better spectral resolution than conventional approaches, which helps reveal details of the paramagnetic molecules' chemical structure that were not accessible before.
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Affiliation(s)
- Nir Dayan
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - Yaron Artzi
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - Moamen Jbara
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - David Cristea
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, 3200003, Haifa, Israel
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3
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Abhyankar N, Agrawal A, Campbell J, Maly T, Shrestha P, Szalai V. Recent advances in microresonators and supporting instrumentation for electron paramagnetic resonance spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:101101. [PMID: 36319314 PMCID: PMC9632321 DOI: 10.1063/5.0097853] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 08/13/2022] [Indexed: 06/16/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy characterizes the magnetic properties of paramagnetic materials at the atomic and molecular levels. Resonators are an enabling technology of EPR spectroscopy. Microresonators, which are miniaturized versions of resonators, have advanced inductive-detection EPR spectroscopy of mass-limited samples. Here, we provide our perspective of the benefits and challenges associated with microresonator use for EPR spectroscopy. To begin, we classify the application space for microresonators and present the conceptual foundation for analysis of resonator sensitivity. We summarize previous work and provide insight into the design and fabrication of microresonators as well as detail the requirements and challenges that arise in incorporating microresonators into EPR spectrometer systems. Finally, we provide our perspective on current challenges and prospective fruitful directions.
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Affiliation(s)
| | - Amit Agrawal
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jason Campbell
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Thorsten Maly
- Bridge12 Technologies, Inc., Natick, Massachusetts 01760, USA
| | | | - Veronika Szalai
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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4
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Artzi Y, Yishay Y, Fanciulli M, Jbara M, Blank A. Superconducting micro-resonators for electron spin resonance - the good, the bad, and the future. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 334:107102. [PMID: 34847488 DOI: 10.1016/j.jmr.2021.107102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/17/2021] [Accepted: 10/30/2021] [Indexed: 06/13/2023]
Abstract
The field of electron spin resonance (ESR) is in constant need of improving its capabilities. Among other things, this means having better resonators to reach improved spin sensitivity and enable larger microwave-power-to-microwave-magnetic-field conversion factors. Surface micro-resonators, made of small metallic patches on a dielectric substrate, provide very good absolute spin sensitivity and high conversion factors due to their very small mode volume. However, such resonators suffer from relatively low spin concentration sensitivity and a low-quality factor, a fact that offsets some of their significant potential advantages. The use of superconducting patches to replace the metallic layer seems a reasonable and straightforward solution to the quality factor issue, at least for measurements carried out at cryogenic temperatures. Nevertheless, superconducting materials, especially those that can operate at moderate cryogenic temperatures, are not easily incorporated into setups requiring high magnetic fields due to the electric current vortices generated in the latter's surface. This makes the transition from normal conducting materials to superconductors highly nontrivial. Here we present the design, fabrication, and testing results of surface micro-resonators made of yttrium barium copper oxide (YBCO), a superconducting material that operates also at high magnetic fields and makes it possible to pursue ESR at moderate cryogenic temperatures (up to ∼ 80 K). We show that with a unique experimental setup, these resonators can be made to operate well even at high fields of ∼ 1.2 T. Furthermore, we analyze the effect of current vortices on the ESR signal and the spins' coherence times. Finally, we provide a head-to-head comparison of YBCO vs copper resonators of the same dimensions, which clearly shows their pros and cons and directs us to future potential developments and improvements in this field.
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Affiliation(s)
- Yaron Artzi
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Yakir Yishay
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Marco Fanciulli
- Department of Materials Science, University of Milano - Bicocca, Italy
| | - Moamen Jbara
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
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5
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Nogaret A, Stebliy M, Portal JC, Beere HE, Ritchie DA. Ballistic Hall Photovoltammetry of Magnetic Resonance in Individual Nanomagnets. PHYSICAL REVIEW LETTERS 2021; 126:207701. [PMID: 34110191 DOI: 10.1103/physrevlett.126.207701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 03/20/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
We report on ballistic Hall photovoltammetry as a contactless probe of localized spin excitations. Spins resonating in the near field of a two-dimensional electron system are shown to induce a long range electromotive force that we calculate. We use this coupling mechanism to detect the spin wave eigenmodes of a single ferromagnet of sub-100 nm size. The high sensitivity of this detection technique, 380 spins/sqrt[Hz], and its noninvasiveness present advantages for probing magnetization dynamics and spin transport.
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Affiliation(s)
- Alain Nogaret
- Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
| | - Maksym Stebliy
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690091, Russia
| | - Jean-Claude Portal
- High Magnetic Field Laboratory, Centre National de la Recherche Scientifique, 25 Avenue des Martyrs, Grenoble 38042, France
| | - Harvey E Beere
- Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - David A Ritchie
- Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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6
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Syryamina VN, Matveeva AG, Vasiliev YV, Savitsky A, Grishin YA. Improving B 1 field homogeneity in dielectric tube resonators for EPR spectroscopy via controlled shaping of the dielectric insert. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 311:106685. [PMID: 31981782 DOI: 10.1016/j.jmr.2020.106685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
We propose an approach for improving the homogeneity of microwave magnetic field amplitude in a dielectric tube resonator for electron paramagnetic resonance spectroscopy at X-band. The improvement is achieved by "shaping" (controllable variation of the outer diameter of a dielectric insert along its axial direction). Various shaping scenarios based on the principle of discrete solenoids and electromagnetic calculations have been considered. The dielectric insert having the most promising shape was manufactured from a bismuth germanate single crystal. The shaped insert increases the area at B1 > 0.9 B1max from 5.06 to 7.36 mm. Higher sensitivity and lower likelihood of quantitative errors have been achieved in pulse EPR experiments for "long" samples (whose length was comparable to that of the dielectric insert) in a shaped dielectric insert.
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Affiliation(s)
- Victoria N Syryamina
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya Str., 3, 630090 Novosibirsk, Russia; Novosibirsk State University, Pirogova Str., 2, 630090 Novosibirsk, Russia.
| | - Anna G Matveeva
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya Str., 3, 630090 Novosibirsk, Russia; Novosibirsk State University, Pirogova Str., 2, 630090 Novosibirsk, Russia
| | - Yan V Vasiliev
- Nikolaev Institute of Inorganic Chemistry, Acad. Lavrentiev Av., 3, 630090 Novosibirsk, Russia
| | - Anton Savitsky
- Physics Department, Technical University of Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany
| | - Yuri A Grishin
- Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya Str., 3, 630090 Novosibirsk, Russia; Novosibirsk State University, Pirogova Str., 2, 630090 Novosibirsk, Russia
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7
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Sidabras JW, Duan J, Winkler M, Happe T, Hussein R, Zouni A, Suter D, Schnegg A, Lubitz W, Reijerse EJ. Extending electron paramagnetic resonance to nanoliter volume protein single crystals using a self-resonant microhelix. SCIENCE ADVANCES 2019; 5:eaay1394. [PMID: 31620561 PMCID: PMC6777973 DOI: 10.1126/sciadv.aay1394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/06/2019] [Indexed: 05/26/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy on protein single crystals is the ultimate method for determining the electronic structure of paramagnetic intermediates at the active site of an enzyme and relating the magnetic tensor to a molecular structure. However, crystals of dimensions typical for protein crystallography (0.05 to 0.3mm) provide insufficient signal intensity. In this work, we present a microwave self-resonant microhelix for nanoliter samples that can be implemented in a commercial X-band (9.5 GHz) EPR spectrometer. The self-resonant microhelix provides a measured signal-to-noise improvement up to a factor of 28 with respect to commercial EPR resonators. This work opens up the possibility to use advanced EPR techniques for studying protein single crystals of dimensions typical for x-ray crystallography. The technique is demonstrated by EPR experiments on single crystal [FeFe]-hydrogenase (Clostridium pasteurianum; CpI) with dimensions of 0.3 mm by 0.1 mm by 0.1 mm, yielding a proposed g-tensor orientation of the Hox state.
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Affiliation(s)
- Jason W. Sidabras
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Jifu Duan
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Martin Winkler
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Thomas Happe
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Rana Hussein
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - Dieter Suter
- Experimentelle Physik, Technische Universität Dortmund, Emil-Figge-Straße 50, 44221 Dortmund, Germany
| | - Alexander Schnegg
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Edward J. Reijerse
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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8
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Eisenach ER, Barry JF, Pham LM, Rojas RG, Englund DR, Braje DA. Broadband loop gap resonator for nitrogen vacancy centers in diamond. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:094705. [PMID: 30278724 DOI: 10.1063/1.5037465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/31/2018] [Indexed: 06/08/2023]
Abstract
We present an S-band tunable loop gap resonator (LGR), which provides strong, homogeneous, and directionally uniform broadband microwave (MW) drive for nitrogen-vacancy (NV) ensembles. With 42 dBm of input power, the composite device provides drive field amplitudes approaching 5 G over a circular area ≳50 mm2 or cylindrical volume ≳250 mm3. The wide 80 MHz device bandwidth allows driving all NV Zeeman resonances for bias magnetic fields below 20 G. The device realizes percent-scale MW drive inhomogeneity; we measure a fractional root-mean-square inhomogeneity σ rms = 1.6% and a peak-to-peak variation σ pp = 3% over a circular area of 11 mm2 and σ rms = 3.2% and σ pp = 10.5% over a larger 32 mm2 circular area. We demonstrate incident MW power coupling to the LGR using two methodologies: a printed circuit board-fabricated exciter antenna for deployed compact bulk sensors and an inductive coupling coil suitable for microscope-style imaging. The inductive coupling coil allows for approximately 2π steradian combined optical access above and below the device, ideal for envisioned and existing NV imaging and bulk sensing applications.
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Affiliation(s)
- E R Eisenach
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J F Barry
- MIT Lincoln Laboratory, Lexington, Massachusetts 02421, USA
| | - L M Pham
- MIT Lincoln Laboratory, Lexington, Massachusetts 02421, USA
| | - R G Rojas
- MIT Lincoln Laboratory, Lexington, Massachusetts 02421, USA
| | - D R Englund
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - D A Braje
- MIT Lincoln Laboratory, Lexington, Massachusetts 02421, USA
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9
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Zgadzai O, Twig Y, Wolfson H, Ahmad R, Kuppusamy P, Blank A. Electron-Spin-Resonance Dipstick. Anal Chem 2018; 90:7830-7836. [PMID: 29856211 DOI: 10.1021/acs.analchem.8b00917] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electron spin resonance (ESR) is a powerful analytical technique used for the detection, quantification, and characterization of paramagnetic species ranging from stable organic free radicals and defects in crystals to gaseous oxygen. Traditionally, ESR requires the use of complex instrumentation, including a large magnet and a microwave resonator in which the sample is placed. Here, we present an alternative to the existing approach by inverting the typical measurement topology, namely placing the ESR magnet and resonator inside the sample rather than the other way around. This new development relies on a novel self-contained ESR sensor with a diameter of just 2 mm and length of 3.6 mm, which includes both a small permanent magnet assembly and a tiny (∼1 mm in size) resonator for spin excitation and detection at a frequency of ∼2.6 GHz. The spin sensitivity of the sensor has been measured to be ∼1011 spins/√Hz, and its concentration sensitivity is ∼0.1 mM, using reference samples with a measured volume of just ∼10 nL. Our new approach can be applied for monitoring the partial pressure of oxygen in vitro and in vivo through its paramagnetic interaction with another stable radical, as well as for simple online quantitative inspection of free radicals generated in reaction vessels and electrochemical cells via chemical processes.
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Affiliation(s)
- Oleg Zgadzai
- Schulich Faculty of Chemistry , Technion - Israel Institute of Technology , Haifa 3200008 , Israel
| | - Ygal Twig
- Schulich Faculty of Chemistry , Technion - Israel Institute of Technology , Haifa 3200008 , Israel
| | - Helen Wolfson
- Schulich Faculty of Chemistry , Technion - Israel Institute of Technology , Haifa 3200008 , Israel
| | - Rizwan Ahmad
- Department of Biomedical Engineering , Ohio State University , Columbus , Ohio 43210 , United States
| | - Periannan Kuppusamy
- Departments of Radiology and Medicine, Geisel School of Medicine , Dartmouth College , Lebanon , New Hampshire 03756 , United States
| | - Aharon Blank
- Schulich Faculty of Chemistry , Technion - Israel Institute of Technology , Haifa 3200008 , Israel
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10
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Twig Y, Sorkin A, Cristea D, Feintuch A, Blank A. Surface loop-gap resonators for electron spin resonance at W-band. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:123901. [PMID: 29289191 DOI: 10.1063/1.5000946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electron spin resonance (ESR) is a spectroscopic method used to detect paramagnetic materials, reveal their structure, and also image their position in a sample. ESR makes use of a large static magnetic field to split the energy levels of the electron magnetic moment of the paramagnetic species. A strong microwave magnetic field is applied to excite the spins, and subsequently the ESR system detects their faint microwave signal response. The sensitivity of an ESR system is greatly influenced by the magnitude of the static field and the properties of the microwave resonator used to detect the spin signal. In general terms, the higher the static field (microwave frequency) and the smaller the resonator, the more sensitive the system will be. Previous work aimed at high-sensitivity ESR was focused on the development and testing of very small resonators operating at moderate magnetic fields in the range of ∼0.1-1.2 T (maximum frequency of ∼35 GHz). Here, we describe the design, construction, and testing of recently developed miniature surface loop-gap resonators used in ESR and operating at a much higher frequency of ∼95 GHz (W-band, corresponding to a field of ∼3.4 T). Such resonators can greatly enhance the sensitivity of ESR and also improve the resulting spectral resolution due to the higher static field employed. A detailed description of the resonator's design and coupling mechanism, as well as the supporting probe head, is provided. We also discuss the production method of the resonators and probe head and, in the end, provide preliminary experimental results that show the setup's high spin sensitivity and compare it to theoretical predictions.
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Affiliation(s)
- Ygal Twig
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Anton Sorkin
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - David Cristea
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Akiva Feintuch
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
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11
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Blank A, Twig Y, Ishay Y. Recent trends in high spin sensitivity magnetic resonance. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 280:20-29. [PMID: 28545918 DOI: 10.1016/j.jmr.2017.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/22/2017] [Accepted: 02/26/2017] [Indexed: 06/07/2023]
Abstract
Magnetic resonance is a very powerful methodology that has been employed successfully in many applications for about 70years now, resulting in a wealth of scientific, technological, and diagnostic data. Despite its many advantages, one major drawback of magnetic resonance is its relatively poor sensitivity and, as a consequence, its bad spatial resolution when examining heterogeneous samples. Contemporary science and technology often make use of very small amounts of material and examine heterogeneity on a very small length scale, both of which are well beyond the current capabilities of conventional magnetic resonance. It is therefore very important to significantly improve both the sensitivity and the spatial resolution of magnetic resonance techniques. The quest for higher sensitivity led in recent years to the development of many alternative detection techniques that seem to rival and challenge the conventional "old-fashioned" induction-detection approach. The aim of this manuscript is to briefly review recent advances in the field, and to provide a quantitative as well as qualitative comparison between various detection methods with an eye to future potential advances and developments. We first offer a common definition of sensitivity in magnetic resonance to enable proper quantitative comparisons between various detection methods. Following that, up-to-date information about the sensitivity capabilities of the leading recently-developed detection approaches in magnetic resonance is provided, accompanied by a critical comparison between them and induction detection. Our conclusion from this comparison is that induction detection is still indispensable, and as such, it is very important to look for ways to significantly improve it. To do so, we provide expressions for the sensitivity of induction-detection, derived from both classical and quantum mechanics, that identify its main limiting factors. Examples from current literature, as well as a description of new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.
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Affiliation(s)
- Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel.
| | - Ygal Twig
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Yakir Ishay
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
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12
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Ivanov MY, Nadolinny VA, Bagryanskaya EG, Grishin YA, Fedin MV, Veber SL. Bismuth germanate as a perspective material for dielectric resonators in EPR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 271:83-89. [PMID: 27569694 DOI: 10.1016/j.jmr.2016.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
High purity bismuth germanate (Bi4(GeO4)3, BGO) is proposed and implemented as an alternative material for dielectric EPR resonators. A significant improvement of the absolute sensitivity can be readily achieved by substituting the alumina insert (ring) by BGO-made one in commercially available X-band EPR probeheads. Four BGO dielectric inserts of 2, 3, 4 and 5mm inner diameter (ID) were made for comparison with standard 5mm inner diameter alumina insert. All inserts were introduced into commercial Bruker EPR resonator ER 4118X-MD-5W1, and their performance was investigated. The Q-values of empty resonators, B1 saturation curves and continuous wave EPR spectra of DPPH (2,2-diphenyl-1-picrylhydrazyl) were measured and analyzed in a temperature range 6-300K. BGO-made resonators were found superior in several important aspects. The background signals arising from BGO are much weaker compared to those of alumina at B=0-0.6T and T=6-300K; this is especially useful for measuring weak signals in the half-field region, as well as those near the central field. Moreover, mechanical properties of BGO allow easy fabrication of dielectric bodies having various shapes and sizes; in particular, small BGO resonators (e.g. ID=2 or 3mm) strongly enhance sensitivity for small samples due to increase of the filling factor. All these advantages have been also inspected in the pulse mode, proving that higher B1 fields and better filling factors can be achieved, contributing to the overall enhancement of the performance.
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Affiliation(s)
- Mikhail Y Ivanov
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | | | - Elena G Bagryanskaya
- Novosibirsk State University, Novosibirsk 630090, Russia; N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS, Novosibirsk 630090, Russia
| | - Yuriy A Grishin
- Voevodsky Institute of Chemical Kinetics and Combustion, SB RAS, Novosibirsk 630090, Russia
| | - Matvey V Fedin
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Sergey L Veber
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia.
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13
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Kiss SZ, Rostas AM, Heidinger L, Spengler N, Meissner MV, MacKinnon N, Schleicher E, Weber S, Korvink JG. A microwave resonator integrated on a polymer microfluidic chip. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:169-175. [PMID: 27497077 DOI: 10.1016/j.jmr.2016.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/16/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10mm by 10mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7·10(11)spins·Hz(-1/2)G(-1) for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.
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Affiliation(s)
- S Z Kiss
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - A M Rostas
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - L Heidinger
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - N Spengler
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - M V Meissner
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - N MacKinnon
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - E Schleicher
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - S Weber
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - J G Korvink
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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14
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Hrubesch FM, Braunbeck G, Voss A, Stutzmann M, Brandt MS. Broadband electrically detected magnetic resonance using adiabatic pulses. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 254:62-69. [PMID: 25828243 DOI: 10.1016/j.jmr.2015.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 06/04/2023]
Abstract
We present a broadband microwave setup for electrically detected magnetic resonance (EDMR) based on microwave antennae with the ability to apply arbitrarily shaped pulses for the excitation of electron spin resonance (ESR) and nuclear magnetic resonance (NMR) of spin ensembles. This setup uses non-resonant stripline structures for on-chip microwave delivery and is demonstrated to work in the frequency range from 4 MHz to 18 GHz. π pulse times of 50 ns and 70 μs for ESR and NMR transitions, respectively, are achieved with as little as 100 mW of microwave or radiofrequency power. The use of adiabatic pulses fully compensates for the microwave magnetic field inhomogeneity of the stripline antennae, as demonstrated with the help of BIR4 unitary rotation pulses driving the ESR transition of neutral phosphorus donors in silicon and the NMR transitions of ionized phosphorus donors as detected by electron nuclear double resonance (ENDOR).
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Affiliation(s)
- F M Hrubesch
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
| | - G Braunbeck
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
| | - A Voss
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
| | - M Stutzmann
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
| | - M S Brandt
- Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
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15
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Woflson H, Ahmad R, Twig Y, Williams B, Blank A. A magnetic resonance probehead for evaluating the level of ionizing radiation absorbed in human teeth. HEALTH PHYSICS 2015; 108:326-335. [PMID: 25627944 DOI: 10.1097/hp.0000000000000187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A miniature electron spin resonance (ESR) probehead that includes a static field source and a microwave resonator for in vivo measurement of paramagnetic defects in tooth enamel was developed. These defects are known to be a good marker for quantifying the ionizing radiation dose absorbed in teeth. The probehead has a typical length of just 30 mm and total weight of 220 g. The patient "bites" into the probehead while the measurement procedure is being carried out. The probehead operates in pulsed mode at a frequency of ∼ 11.2 GHz and supplies a static magnetic field of ∼ 400 mT. A detailed design of the probehead is provided together with its specifications in terms of measurement volume and signal-to-noise ratio for a typical sample. A specially developed simulation program was used to predict the spatial distribution of the acquired signal under conditions of grossly inhomogeneous static and RF fields. Experimental results with irradiated incisor teeth validated the probehead's sensitivity, being able to detect signals in tooth irradiated by only 2 Gy. Subject to additional improvements and tests, this type of probehead can potentially have significant clinical applications ranging from mass triage following major nuclear events to routine occupational evaluation of ionizing radiation absorbed over long periods of time.
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Affiliation(s)
- Helen Woflson
- *Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel; †Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, 43210; ‡The Geisel School of Medicine at Dartmouth, Departments of Medicine and Radiology, Lebanon, NH 03766
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16
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Narkowicz R, Suter D. Tuner and radiation shield for planar electron paramagnetic resonance microresonators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:024701. [PMID: 25725864 DOI: 10.1063/1.4906898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Planar microresonators provide a large boost of sensitivity for small samples. They can be manufactured lithographically to a wide range of target parameters. The coupler between the resonator and the microwave feedline can be integrated into this design. To optimize the coupling and to compensate manufacturing tolerances, it is sometimes desirable to have a tuning element available that can be adjusted when the resonator is connected to the spectrometer. This paper presents a simple design that allows one to bring undercoupled resonators into the condition for critical coupling. In addition, it also reduces radiation losses and thereby increases the quality factor and the sensitivity of the resonator.
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Affiliation(s)
| | - Dieter Suter
- Fakultät Physik, TU Dortmund, 44221 Dortmund, Germany
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17
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Quantum Computation with Molecular Nanomagnets: Achievements, Challenges, and New Trends. MOLECULAR NANOMAGNETS AND RELATED PHENOMENA 2014. [DOI: 10.1007/430_2014_145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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18
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Narkowicz R, Ogata H, Reijerse E, Suter D. A cryogenic receiver for EPR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 237:79-84. [PMID: 24161681 DOI: 10.1016/j.jmr.2013.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/24/2013] [Accepted: 09/26/2013] [Indexed: 06/02/2023]
Abstract
Cryogenic probes have significantly increased the sensitivity of NMR. Here, we present a compact EPR receiver design capable of cryogenic operation. Compared to room temperature operation, it reduces the noise by a factor of ≈2.5. We discuss in detail the design and analyze the resulting noise performance. At low microwave power, the input noise density closely follows the emission of a cooled 50Ω resistor over the whole measurement range from 20K up to room temperature. To minimize the influence of the microwave source noise, we use high microwave efficiency (≈1.1-1.7mTW(-1/2)) planar microresonators. Their efficient conversion of microwave power to magnetic field permits EPR measurements with very low power levels, typically ranging from a few μW down to fractions of nW.
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Affiliation(s)
- R Narkowicz
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, D-44221 Dortmund, Germany.
| | - H Ogata
- Max-Planck Institute for Chemical Energy Conversion, Stiftsraße 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - E Reijerse
- Max-Planck Institute for Chemical Energy Conversion, Stiftsraße 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - D Suter
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, D-44221 Dortmund, Germany
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19
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Yap YS, Yamamoto H, Tabuchi Y, Negoro M, Kagawa A, Kitagawa M. Strongly driven electron spins using a K(u) band stripline electron paramagnetic resonance resonator. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 232:62-67. [PMID: 23703225 DOI: 10.1016/j.jmr.2013.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/23/2013] [Accepted: 04/26/2013] [Indexed: 06/02/2023]
Abstract
This article details our work to obtain strong excitation for electron paramagnetic resonance (EPR) experiments by improving the resonator's efficiency. The advantages and application of strong excitation are discussed. Two 17 GHz transmission-type, stripline resonators were designed, simulated and fabricated. Scattering parameter measurements were carried out and quality factor were measured to be around 160 and 85. Simulation results of the microwave's magnetic field distribution are also presented. To determine the excitation field at the sample, nutation experiments were carried out and power dependence were measured using two organic samples at room temperature. The highest recorded Rabi frequency was rated at 210 MHz with an input power of about 1 W, which corresponds to a π/2 pulse of about 1.2 ns.
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Affiliation(s)
- Yung Szen Yap
- Graduate School of Engineering Science, Osaka University, Japan.
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20
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Twig Y, Dikarov E, Blank A. Ultra miniature resonators for electron spin resonance: Sensitivity analysis, design and construction methods, and potential applications. Mol Phys 2013. [DOI: 10.1080/00268976.2012.762463] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Twig Y, Dikarov E, Blank A. Cryogenic electron spin resonance microimaging probe. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 218:22-29. [PMID: 22578551 DOI: 10.1016/j.jmr.2012.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 02/09/2012] [Accepted: 03/13/2012] [Indexed: 05/31/2023]
Abstract
A new probe for acquiring ESR images with microscopic resolution and high spin sensitivity, at a temperature range of ~4.2-300 K, is presented. Details of the probe design, as well as its principle of operation, are provided. The probe incorporates a unique surface loop-gap microresonator. Experimental results demonstrate the system's capability to acquire two - as well as three-dimensional images with a flat test sample of phosphorus-doped silicon. The imaging results also allow verifying the resonator's resonance mode - they show its B(1) distribution, which also makes it possible to estimate the number of spins measured in the sample.
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Affiliation(s)
- Ygal Twig
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
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22
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Anders J, Angerhofer A, Boero G. K-band single-chip electron spin resonance detector. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 217:19-26. [PMID: 22405529 DOI: 10.1016/j.jmr.2012.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 05/31/2023]
Abstract
We report on the design, fabrication, and characterization of an integrated detector for electron spin resonance spectroscopy operating at 27 GHz. The microsystem, consisting of an LC-oscillator and a frequency division module, is integrated onto a single silicon chip using a conventional complementary metal-oxide-semiconductor technology. The achieved room temperature spin sensitivity is about 10(8)spins/G Hz(1/2), with a sensitive volume of about (100 μm)(3). Operation at 77K is also demonstrated.
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Affiliation(s)
- Jens Anders
- Ecole Polytechninque Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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23
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Twig Y, Dikarov E, Hutchison WD, Blank A. Note: High sensitivity pulsed electron spin resonance spectroscopy with induction detection. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:076105. [PMID: 21806239 DOI: 10.1063/1.3611003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Commercial electron spin resonance spectroscopy and imaging systems make use of the so-called "induction" or "Faraday" detection, which is based on a radio frequency coil or a microwave resonator. The sensitivity of induction detection does not exceed ~3 × 10(8) spins/√Hz. Here we show that through the use of a new type of surface loop-gap microresonators (inner size of 20 μm), operating at cryogenic temperatures at a field of 0.5 T, one can improve upon this sensitivity barrier by more than 2 orders of magnitude and reach spin sensitivities of ~1.5 × 10(6) spins/√Hz or ~2.5 × 10(4) spins for 1 h.
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Affiliation(s)
- Ygal Twig
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
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24
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Shtirberg L, Twig Y, Dikarov E, Halevy R, Levit M, Blank A. High-sensitivity Q-band electron spin resonance imaging system with submicron resolution. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:043708. [PMID: 21529014 DOI: 10.1063/1.3581226] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A pulsed electron spin resonance (ESR) microimaging system operating at the Q-band frequency range is presented. The system includes a pulsed ESR spectrometer, gradient drivers, and a unique high-sensitivity imaging probe. The pulsed gradient drivers are capable of producing peak currents ranging from ∼9 A for short 150 ns pulses up to more than 94 A for long 1400 ns gradient pulses. Under optimal conditions, the imaging probe provides spin sensitivity of ∼1.6 × 10(8) spins∕√Hz or ∼2.7 × 10(6) spins for 1 h of acquisition. This combination of high gradients and high spin sensitivity enables the acquisition of ESR images with a resolution down to ∼440 nm for a high spin concentration solid sample (∼10(8) spins∕μm(3)) and ∼6.7 μm for a low spin concentration liquid sample (∼6 × 10(5) spins/μm(3)). Potential applications of this system range from the imaging of point defects in crystals and semiconductors to measurements of oxygen concentration in biological samples.
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Affiliation(s)
- Lazar Shtirberg
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
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