Continuous-wave far-infrared ESR spectrometer for high-pressure measurements

Náfrádi, Bálint; Gáal, R.; Sienkiewicz, Andrzej; Fehér, Titusz; Forró, Lászlø

doi:10.1016/j.jmr.2008.09.014

Cited by 36 publications

(26 citation statements)

References 29 publications

(49 reference statements)

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“…Significant developments of high-field quasi-optical ESR are ongoing, 32,33,[36][37][38][39][40] where cw ESR has evolved up to f hν = 750 GHz 41 and free electron lasers (FEL) can provide highest irradiation power (several kW) in pulsed or quasi-cw high-field ESR. [42][43][44][45] However, these spectrometers are highly specialized and operate in one dedicated high-field environment, 41 and a very recent commercial system provides a high ESR sensitivity but narrow (0.2 T) field sweep range.…”

Section: Improving Electron Spin Resonance (Esr)mentioning

confidence: 99%

Field and frequency modulated sub-THz electron spin resonance spectrometer

et al. 2016

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260-GHz radiation is used for a quasi-optical electron spin resonance (ESR) spectrometer which features both field and frequency modulation. Free space propagation is used to implement Martin-Puplett interferometry with quasi-optical isolation, mirror beam focusing, and electronic polarization control. Computer-aided design and polarization pathway simulation lead to the design of a compact interferometer, featuring lateral dimensions less than a foot and high mechanical stability, with all components rated for power levels of several Watts suitable for gyrotron radiation. Benchmark results were obtained with ESR standards (BDPA, DPPH) using field modulation. Original high-field ESR of 4f electrons in Sm3+-doped Ceria was detected using frequency modulation. Distinct combinations of field and modulation frequency reach a signal-to-noise ratio of 35 dB in spectra of BDPA, corresponding to a detection limit of about 1014 spins.

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Section: Improving Electron Spin Resonance (Esr)mentioning

confidence: 99%

Field and frequency modulated sub-THz electron spin resonance spectrometer

et al. 2016

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“…ESR was performed by homebuilt spectrometers operating at 111.2 and 222.4 GHz frequencies [18][19][20] . These setups are particularly suitable to detect the AFM resonance in organic magnets.…”

Section: Methodsmentioning

confidence: 99%

Frustration-induced one-dimensionality in the isosceles triangular antiferromagnetic lattice of δ -(EDT-TTF- CONMe2)2AsF6

et al. 2016

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The 1/4-filled organic compound, δ-(EDT-TTF-CONMe2)2AsF6 is a frustrated two-dimensional triangular magnetic system as shown by high-frequency (111.2 and 222.4 GHz) electron spin resonance (ESR) and structural data in the literature. The material gradually orders antiferromagnetically below 40 K but some magnetically disordered domains persist down to 4 K. We propose that in defect free regions frustration prevents true magnetic order down to at least 4 K in spite of the large first-and second-neighbor exchange interactions along chains and between chains, respectively. The antiferromagnetic (AFM) order gradually developing below 40 K nucleates around structural defects that locally cancel frustration. Two antiferromagnetic resonance modes mapped in the principal planes at 4 K are assigned to the very weakly interacting one-dimensional molecular chains in antiferromagnetic regions.

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“…It is worth mentioning that this calibration method has rarely been used in the high-pressure ESR systems already described, because the Q value of the cavity is lowered by the insertion of metal such as tin. Although the calibration by ruby fluorescence was adopted in some high-pressure ESR systems [9,11,27], it is not adequate in the relatively lower pressure range like that in which the piston cylinder pressure cell works, because the accuracy is poor in such a pressure range. Therefore, in many high-pressure ESR systems, except for several systems using ruby fluorescence, the calibration method has not been fully established.…”

Section: Outline Of Setupmentioning

confidence: 99%

“…For instance, we have revealed the precise pressure dependences of the spin gaps, which are far above 10 GHz at ambient pressure, for the spin dimer system KCuCl 3 which is known to realize the magnon Bose-Einstein condensation [23], and for the Shastry-Sutherland model substance SrCu 2 (BO 3 ) 2 which is known to show sequence magnetization plateaux [25,26]. Another group has also developed a high-pressure and high-field ESR system using the quasi-optics method, and they showed that obtaining high resolution of the g-value is very useful for measurements of the organic conductor having small g-value anisotropy [27,28].…”

Section: Introductionmentioning

confidence: 99%