Zero-field NMR J-Spectroscopy of Organophosphorus Compounds

10.26434/chemrxiv.13286477.v1 ◽

2020 ◽

Author(s):

Seyma Alcicek ◽

Piotr Put ◽

Vladimir Kontul ◽

Szymon Pustelny

Keyword(s):

Magnetic Field ◽

Organophosphorus Compounds ◽

Spin Dynamics ◽

Experimental Studies ◽

Spin Systems ◽

Zero Field ◽

Single Measurement ◽

Low Field ◽

J Coupling ◽

Low Field Nmr

In this paper, we report the results of theoretical and experimental studies on basic organophosphorus compounds using zero-field NMR, where spin dynamics are investigated in the absence of a magnetic field with the dominant heteronuclear J-coupling. We demonstrate that the zero-field NMR enables distinguishing the chemicals owing to their unique electronic environment even for identical spin systems. Such information can be obtained just in a single measurement, while amplitudes and widths of observed low-field NMR resonances enable to study of processes affecting spin dynamics. An excellent agreement between simulations and measurements of the spectra, particularly in the largest frequency J-couplings range ever reported in zero-field NMR is demonstrated.

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Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

Scientific Reports ◽

10.1038/s41598-021-86353-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Matúš Orendáč ◽

Slavomír Gabáni ◽

Pavol Farkašovský ◽

Emil Gažo ◽

Jozef Kačmarčík ◽

...

Keyword(s):

Magnetic Field ◽

Phase Diagram ◽

Ground State ◽

Constant Magnetic Field ◽

Paramagnetic Phase ◽

The Other ◽

Zero Field ◽

Plateau Phase ◽

Low Field ◽

Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

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Low-Field NMR Relaxation Times Distributions and Their Magnetic Field Dependence as a Possible Biomarker in Cartilage

EMBEC & NBC 2017 - IFMBE Proceedings ◽

10.1007/978-981-10-5122-7_238 ◽

2017 ◽

pp. 952-955 ◽

Cited By ~ 1

Author(s):

Oleg V. Petrov ◽

Erik Rössler ◽

Carlos Mattea ◽

Miika T. Nieminen ◽

Petri Lehenkari ◽

...

Keyword(s):

Magnetic Field ◽

Field Dependence ◽

Magnetic Field Dependence ◽

Relaxation Times ◽

Nmr Relaxation ◽

Low Field ◽

Nmr Relaxation Times ◽

Low Field Nmr

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Magnetism of Bismuth(III) Oxide-Based Compounds

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.233-234.113 ◽

2015 ◽

Vol 233-234 ◽

pp. 113-116

Author(s):

Eleonora A. Kravchenko

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Spin Dynamics ◽

Spin Echo ◽

Magnetic Moments ◽

Fold Increase ◽

Zero Field ◽

Line Shapes ◽

Nuclear Magnetic Moments ◽

Magnetic Splitting

209Bi NQR experiments, including analysis of zero-field line shapes, Zeeman-perturbed patterns and zero-field spin-echo envelopes were made to examine magnetic splitting of resonances revealed in the spectra of Main group element compounds of general composition BakBilAmOn (A=Al, В, Ge, Br, Cl). The results were explained assuming the existence in the compounds of ordered internal magnetic fields from 5 to 250 G which notably exceed those of nuclear magnetic moments. A dramatic (8−10-fold) increase in the resonance intensities, instead of broadening and fading, was observed for such compounds upon applying weak (below 500 Oe) external magnetic fields. The effect was shown to relate to the spin dynamics, namely, to the influence of external magnetic field on the nuclear spin-spin relaxation of the compounds with anomalous magnetic properties. In α-Bi2O3, paramagnetism depending on the thermal prehistory of a sample was found using SQUID-technique; magnetoelectric effect linear in magnetic field was also observed for this oxide.

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Anomalous Low-Field Magnetic Behaviour of High-TC Superconductors

MRS Proceedings ◽

10.1557/proc-275-317 ◽

1992 ◽

Vol 275 ◽

Cited By ~ 1

Author(s):

M. F. Tai ◽

H. J. Wang ◽

C. C. Lin ◽

H. L. Wang

Keyword(s):

Magnetic Field ◽

Magnetic Properties ◽

Low Temperature ◽

Low Frequency ◽

Magnetic Behaviour ◽

Zero Field ◽

Field Range ◽

Low Field ◽

Complex Susceptibility ◽

Applied Fields

ABSTRACTWe report on the studies of low-field magnetic properties in the well-characteristic superconducting LaCaBaCu3Oy, YBa2Cu3Oy, YaBa4Cu8Oy, (La1–85Sr0–15)CuO4-y, (Tl0–5Pb0–5)Ca2Sr2Cu3Oy and (Bi2−xPbx)Ca2Sr2Cu3Oy oxides. The studies of magnetic properties include ac zero-field cooled (ZFC), field-cooled (FC), and ac susceptibilities, and their dependences on the applied magnetic field and temperature. As the applied dc magnetic field is low enough, the FC susceptibility varies flat with the increasing of temperature from low temperature, but the diamagnetic signal becomes increasing at some temperature and reaches to the maximum values, and then continously decreases with temperature, at last the diamagnetism rapidly transfers to paramagnetism with temperature going to above Tc. The magnetization reduction at low temperature significantly appears at the low dc magnetic field and exists within a lot of single-phase high-Tc superconductors. However, this phenomenon is not observed in the measurements of low-frequency ac complex susceptibility for the ac applied fields from 0.001 G to 10 G and disappears for higher dc applied field. But, there exists a two-step drop in ac and ZFC susceptibilities curve and the drop correlates with the de FC magnetization dip. The magnetic field range of the dip occurrence is dependent on specimens. The strange magnetic property may be regard with superconducting coupling link in grain boundaries and interpreted by the grain-cluster model associated with Josephson effect.

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Chip-Scale Ultra-Low Field Atomic Magnetometer Based on Coherent Population Trapping

Sensors ◽

10.3390/s21041517 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1517

Author(s):

Hyun-Gue Hong ◽

Sang Eon Park ◽

Sang-Bum Lee ◽

Myoung-Sun Heo ◽

Jongcheol Park ◽

...

Keyword(s):

Magnetic Field ◽

Ground State ◽

Coherent Population Trapping ◽

Zero Magnetic Field ◽

Zero Field ◽

Resonance Signal ◽

Low Field ◽

Low Magnetic Field ◽

Population Trapping ◽

Wide Operating

We report a chip-scale atomic magnetometer based on coherent population trapping, which can operate near zero magnetic field. By exploiting the asymmetric population among magnetic sublevels in the hyperfine ground state of cesium, we observe that the resonance signal acquires sensitivity to magnetic field in spite of degeneracy. A dispersive signal for magnetic field discrimination is obtained near-zero-field as well as for finite fields (tens of micro-tesla) in a chip-scale device of 0.94 cm3 volume. This shows that it can be readily used in low magnetic field environments, which have been inaccessible so far in miniaturized atomic magnetometers based on coherent population trapping. The measured noise floor of 300 pT/Hz1/2 at the zero-field condition is comparable to that of the conventional finite-field measurement obtained under the same conditions. This work suggests a way to implement integrated atomic magnetometers with a wide operating range.

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