scholarly journals Hyperfine spectroscopy in a quantum-limited spectrometer

2020 ◽  
Vol 1 (2) ◽  
pp. 315-330
Author(s):  
Sebastian Probst ◽  
Gengli Zhang ◽  
Miloš Rančić ◽  
Vishal Ranjan ◽  
Marianne Le Dantec ◽  
...  
Keyword(s):  
Hyperfine Coupling ◽  
Spin Echo ◽  
Electron Spin Echo ◽  
High Sensitivity ◽  
Quantitative Agreement ◽  
High Quality ◽  
Spin Concentration ◽  
Erbium Ions ◽  
Millikelvin Temperatures ◽  
Hyperfine Spectroscopy

Abstract. We report measurements of electron-spin-echo envelope modulation (ESEEM) performed at millikelvin temperatures in a custom-built high-sensitivity spectrometer based on superconducting micro-resonators. The high quality factor and small mode volume (down to 0.2 pL) of the resonator allow us to probe a small number of spins, down to 5×102. We measure two-pulse ESEEM on two systems: erbium ions coupled to 183W nuclei in a natural-abundance CaWO4 crystal and bismuth donors coupled to residual 29Si nuclei in a silicon substrate that was isotopically enriched in the 28Si isotope. We also measure three- and five-pulse ESEEM for the bismuth donors in silicon. Quantitative agreement is obtained for both the hyperfine coupling strength of proximal nuclei and the nuclear-spin concentration.

scholarly journals Hyperfine spectroscopy in a quantum-limited spectrometer

2020 ◽  
Author(s):  
Sebastian Probst ◽  
Gengli Zhang ◽  
Miloš Rančić ◽  
Vishal Ranjan ◽  
Marianne Le Dantec ◽  
...  
Keyword(s):  
Hyperfine Coupling ◽  
Spin Echo ◽  
Electron Spin Echo ◽  
High Sensitivity ◽  
Quantitative Agreement ◽  
High Quality ◽  
Spin Concentration ◽  
Erbium Ions ◽  
Millikelvin Temperatures ◽  
Hyperfine Spectroscopy

Abstract. We report measurements of electron spin echo envelope modulation (ESEEM) performed at millikelvin temperatures in a custom-built high-sensitivity spectrometer based on superconducting micro-resonators. The high quality factor and small mode volume (down to 0.2 pL) of the resonator allow to probe a small number of spins, down to 5 ⋅ 102. We measure 2-pulse ESEEM on two systems: erbium ions coupled to 183W nuclei in a natural-abundance CaWO4 crystal, and bismuth donors coupled to residual 29Si nuclei in a silicon substrate that was isotopically enriched in the 28Si isotope. We also measure 3- and 5-pulse ESEEM for the bismuth donors in silicon. Quantitative agreement is obtained for both the hyperfine coupling strength of proximal nuclei, and the nuclear spin concentration.

scholarly journals Characterisation of the Fe(III):H+ Defect Centre in Natural Amethyst

2020 ◽  
Vol 51 (11) ◽  
pp. 1607-1619
Author(s):  
Francesco Di Benedetto ◽  
Alfonso Zoleo ◽  
Maurizio Romanelli
Keyword(s):  
Hyperfine Coupling ◽  
Continuous Wave ◽  
Spin Echo ◽  
Tetrahedral Site ◽  
Electron Spin Echo ◽  
Charge Balance ◽  
Paramagnetic Resonance ◽  
Isotropic Hyperfine Coupling ◽  
Pulsed Electron Paramagnetic Resonance ◽  
Electron Paramagnetic

AbstractA natural single crystal of amethyst was investigated by means of continuous-wave and pulsed Electron Paramagnetic Resonance (EPR), with the aim of structurally characterizing the substitutional S2 Fe(III):H+ centre. In this centre, Fe(III) replaces Si(IV) in the tetrahedral site, whereas H+ is coupled to Fe(III) to maintain the charge balance. The spectroscopic investigations, mainly the interpretation of the Electron Spin Echo Envelope Modulation, allowed a detailed localisation of the proton to be obtained. H+ occurs in the channels crossing the crystal parallel to the crystallographic c axis, in a largely eccentric position. The Fe(III)-H+ distance, evaluated in 2.70 Å, is found associated with a non-negligible isotropic hyperfine coupling, which can be linked to the relative stability of the S2 centre in natural amethyst.

Application of Imaging Plate to High-Voltage Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 168-169
Author(s):  
Seiji Isoda ◽  
Kimitsugu Saitoh ◽  
Sakumi Moriguchi ◽  
Takashi Kobayashi
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
High Sensitivity ◽  
Imaging Plate ◽  
High Quality ◽  
Electron Dose ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Recording Material

On the observation of structures by high resolution electron microscopy, recording materials with high sensitivity and high quality is awaited, especially for the study of radiation sensitive specimens. Such recording material should be easily combined with the minimum dose system and cryoprotection method. Recently a new recording material, imaging plate, comes to be widely used in X-ray radiography and also in electron microscopy, because of its high sensitivity, high quality and the easiness in handling the images with a computer. The properties of the imaging plate in 100 to 400 kV electron microscopes were already discussed and the effectiveness was revealed.It is demanded to study the applicability of the imaging plate to high voltage electron microscopy. The quality of the imaging plate was investigated using an imaging plate system (JEOL EM-HSR100) equipped in a new Kyoto 1000kV electron microscope. In the system both the imaging plate and films can be introduced together into the camera chamber. Figure 1 shows the effect of accelerating voltage on read-out signal intensities from the imaging plate. The characteristic of commercially available imaging plates is unfortunately optimized for 100 to 200 keV electrons and then for 600 to 1000 keV electrons the signal is reduced. In the electron dose range of 10−13 to 10−10 C/cm2, the signal increases linearly with logarithm of electron dose in all acceralating volatges.

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