scholarly journals Measurement of Apparent Spin?Spin Relaxation Times in Nuclear Quadrupole Resonance Using a Double Pulsed Super-regenerative Oscillator

1975 ◽  
Vol 28 (1) ◽  
pp. 45 ◽  
Author(s):  
KR Doolan ◽  
S Hacobian
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Spin Relaxation ◽  
Mathematical Analysis ◽  
Relaxation Times ◽  
Modes Of Operation ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole ◽  
T Values

A super-regenerative oscillator has been used to obtain apparent spin-spin relaxation times n for nuclear quadrupole resonance signals from some polycrystalline compounds. A mathematical analysis is given to show how T~ values may be obtained from a double pulsed super-regenerative oscillator for both logarithmic and linear modes of detection; each of these modes is described. Results obtained from both modes of operation are examined.

Impurity effects on the apparent spin-spin relaxation times of 35Cl nuclear quadrupole resonance in some solid mixtures

1975 ◽  
Vol 28 (7) ◽  
pp. 1439 ◽  
Author(s):  
KR Doolan ◽  
S Hacobian
Keyword(s):  
Relaxation Time ◽  
Nuclear Quadrupole Resonance ◽  
Spin Relaxation ◽  
Relaxation Times ◽  
Electric Quadrupole ◽  
Impurity Effects ◽  
Dipole Interactions ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole ◽  
35Cl Nuclear Quadrupole Resonance

Various monosubstituted and disubstituted benzenes were mixed in varying amounts with p-dichlorobenzene to form solid mixtures. The apparent spin-spin relaxation time, T*2, of the 35Cl nuclear quadrupole resonance of each of these mixtures was determined by a double pulsed super-regenerative oscillator (SRO) method which has been described previously.1 The SRO was operated in the logarithmic mode. The results show that electric quadrupole rather than magnetic dipole interactions are mainly responsible for the broadening that was observed for the 35Cl n.q.r. line of p-dichlorobenzene due to the impurities. The results also indicate that the para-disubstituted benzenes used formed uniform solid solutions with p-dichlorobenzene over the concentration range studied.

scholarly journals Model – free approach to quadrupole spin relaxation in solid 209Bi-aryl compounds

2018 ◽  
Vol 20 (36) ◽  
pp. 23414-23423 ◽  
Author(s):  
Danuta Kruk ◽  
Christian Goesweiner ◽  
Elzbieta Masiewicz ◽  
Evrim Umut ◽  
Carina Sampl ◽  
...  
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Spin Relaxation ◽  
Quadrupole Spin ◽  
Model Free ◽  
Quadrupole Resonance ◽  
Model Free Approach ◽  
Nuclear Quadrupole

Nuclear Quadrupole Resonance (NQR) experiments were performed for deuterated and non-deuterated triphenylbismuth (BiPh3) to inquire into 209Bi relaxation mechanisms.

scholarly journals Tris(2-Methoxyphenyl)Bismuthine Polymorphism Characterized by Nuclear Quadrupole Resonance Spectroscopy

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 446
Author(s):  
Scharfetter ◽  
Fischer ◽  
Krassnig ◽  
Thonhofer ◽  
Theyer ◽  
...  
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Relaxation Times ◽  
Crystallographic Structure ◽  
Resonance Spectroscopy ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Slow Cooling ◽  
Quadrupole Resonance ◽  
Potential Formation ◽  
Nuclear Quadrupole

Based on the previous identification of metastable polymorphs in crystalline triphenylbismuth by nuclear quadrupole resonance spectroscopy (NQRS), the potential formation of similar phases was studied in Tris(2-Methoxyphenyl)Bismuthine. To this end, commercial samples with known NQRS properties were molten and re-crystallized at different speeds (shock freezing in different coolants versus slow cooling inside of a heater). In all recrystallization products we have identified a new crystal phase which has not been observed after synthesis from a solution. The new crystallographic structure has been confirmed by X-ray diffraction (XRD). The newly isolated polymorph crystallizes in the monoclinic space group P2(1)/c with only one molecule in the asymmetric unit and consequently only one 5/2-7/2 transition is observed at 88.75 MHz at 310 K. In contrast, the two transitions at 89.38 and 89.29 MHz for the well-known trigonal polymorph originate from two crystallographically distinct molecules of Tris(2-methoxy-Phenyl)Bismuthine in the asymmetric unit. Additional relaxometric NQRS shows distinctly different T2 relaxation times for the new polymorph when compared to the original samples. Additional phase transitions could not be observed during temperature sweeps between 153K and 323K.

Square wave frequency modulation in pure nuclear quadrupole resonance spectroscopy

1973 ◽  
Vol 26 (8) ◽  
pp. 1611 ◽  
Author(s):  
RA Caldwell
Keyword(s):  
Relaxation Time ◽  
Nuclear Quadrupole Resonance ◽  
Spin Relaxation ◽  
Modulation Frequency ◽  
Spin Relaxation Time ◽  
Resonance Spectroscopy ◽  
Nuclear Quadrupole Resonance Signal ◽  
Square Wave ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

The effect of square wave modulation frequency on the signal intensities obtained with a super-regenerative spectrometer is investigated. The dependence of the nuclear quadrupole resonance signal intensity obtained with a number of compounds is found to be related to the apparent spin-spin relaxation time of the resonant nuclei. An analysis indicates that the signal response of the resonant nuclei is the same regardless of modulation frequency. However, the fundamental Fourier component is directly related to the apparent spin-spin relaxation time.

Cl35spin-spin relaxation timeT2inRb2ZnCl4studied by nuclear quadrupole resonance

1990 ◽  
Vol 41 (10) ◽  
pp. 6213-6219 ◽  
Author(s):  
G. Papavassiliou ◽  
F. Milia ◽  
E. Giannakopoulos
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Spin Relaxation ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole
Sign in / Sign up

Export Citation Format

Share Document