NMR Imaging and the Electric Quadrupole Interaction in Solid Materials

1990 ◽  
Vol 217 ◽  
Author(s):  
B. H. Suits
Keyword(s):  
Quadrupole Interaction ◽  
Relaxation Times ◽  
Electric Quadrupole ◽  
Nmr Imaging ◽  
Electric Quadrupole Interaction ◽  
Electric Field Gradients ◽  
Frequency Shifts ◽  
Field Gradients ◽  
Nuclear Quadrupole Moment ◽  
The Magnetic Field

ABSTRACTNuclei with a spin, 1 > 1/2, possess a nuclear quadrupole moment which can couple to the electric field gradients in a material. They can be static, leading to NMR frequency shifts, or dynamic, which can influence relaxation times. In either case, an NMR image can be made which is sensitized to changes in the electric quadrupole interaction to provide a sensitive measure of the macroscopic spatial dependence of the microscopic changes in the material. Several examples are presented. Special considerations need to be given in the case when the strength of the Zeeman interaction between the nucleus and the magnetic field and/or the rf field is small compared to the electric quadrupole interaction.

Electric Quadrupole Interaction at 181Ta in Isostructural Orthorhombic Cu8Hf3 and Cu8Zr3 Compounds

1998 ◽  
Vol 53 (6-7) ◽  
pp. 355-357
Author(s):  
P. Wodniecki ◽  
B. Wodniecka ◽  
A. Kulińska ◽  
A. Z. Hrynkiewicz
Keyword(s):  
Electric Field ◽  
Quadrupole Interaction ◽  
Perturbed Angular Correlation ◽  
Electric Quadrupole ◽  
Correlation Technique ◽  
Interaction Frequency ◽  
Electric Quadrupole Interaction ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Time Differential

Abstract The quadrupole interaction of 181Ta probes in isostructural Cu8Hf3 and Cu8Zr3 intermetallic compounds was studied in the temperature range 24 K -1100 K with the time-differential perturbed angular correlation technique. Two nonaxial electric field gradients corresponding to two nonequiv-alent hafnium or zirconium sites in the investigated structure were found. A linear decrease in the quadrupole interaction frequency with increase of temperature for the 8(d) sites was evidenced, while the vQ(T) dependence for the 4(c) sites is weaker and has a T3/2 character.

Quadrupole interaction of 181 Ta in Hf compounds

1969 ◽  
Vol 311 (1504) ◽  
pp. 197-206 ◽  
Keyword(s):  
Electric Field ◽  
Field Gradient ◽  
Quadrupole Interaction ◽  
Electric Quadrupole ◽  
Electric Quadrupole Interaction ◽  
Electric Field Gradients ◽  
Correlation Studies ◽  
Field Gradients ◽  
Yield Information ◽  
Time Differential

Time-differential angular correlation studies of the electric quadrupole interaction of 181 Ta in various Hf compounds are presented. Methods for the analysis of the time spectra are discussed. The experiments yield information on the strength of the quadrupole interaction, and on the axial asymmetry and distribution of the field gradient. Electric field gradients V zz are derived for 181 Ta in Hf metal, HfO 2 , and (NH 4 ) 2 HfF 6 .

Spin-echoes in the presence of non-axially symmetric quadrupole interaction in crystals

1955 ◽  
Vol 231 (1185) ◽  
pp. 244-250 ◽  
Keyword(s):  
Electric Field ◽  
Quadrupole Interaction ◽  
Spin Echo ◽  
Electric Quadrupole ◽  
Order Perturbation ◽  
Electric Quadrupole Interaction ◽  
Axially Symmetric ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Spin Echoes

Spin-echo amplitudes for spins I = 1, 3/2 and 5/2 have been worked out in the presence of weak electric quadrupole interaction in crystals with non-axial electric field gradients. The effects of first- and second-order perturbation due to the quadrupole interaction in causing a modulation of the spin-echo signals have been analyzed in detail in comparison with the splitting and shift effects they cause in the steady experiment.

scholarly journals Quadrupole Interaction at Surfaces -Nuclear Methods

1994 ◽  
Vol 49 (1-2) ◽  
pp. 407-417 ◽  
Author(s):  
H. Haas
Keyword(s):  
Mössbauer Spectroscopy ◽  
Quadrupole Interaction ◽  
Mossbauer Spectroscopy ◽  
Electric Quadrupole ◽  
Electric Quadrupole Interaction ◽  
Metallic Surfaces ◽  
Stepped Surfaces ◽  
Mößbauer Spectroscopy ◽  
Field Gradients ◽  
Nuclear Techniques

Abstract The measurement of the electric quadrupole interaction with nuclear techniques allows the study of monolayer coverages or even isolated atoms at surfaces and interfaces due to the inherent sensitivity of these methods. Recently electric field gradients at surface atoms have been investigated with Mößbauer Spectroscopy, Polarized Beam NMR , and Perturbed Angular Correlation (PAC). The highly sensitive PAC technique with 111In and 111mCd sources, in particular, has been applied to several metal and semiconductor surfaces. The use of flat as well as stepped surfaces has allowed the assignment of the measured quadrupole interaction frequencies to specific surface sites. For the Pd(111) surface a particularly complete description is possible, since for five different sites (terrace adatoms, ledge adatoms, kink adatoms, ledge and terrace atoms) the field gradients and their orientation could be determined. They represent a challenging problem for understanding the electronic structure of metallic surfaces. Through the study of the temperature dependence of the different components the diffusion of the radioactive probe atoms can be followed. The data from 57Fe Mößbauer spectroscopy on iron surfaces with monolayer coverage and NMR surface studies of 7Li and 23Na at high temperatures are reviewed. An outlook for further developments of the nuclear techniques is presented, particularly in view of the variety of radioactive isotope beams available from on-line isotope separators like the ISOLDE facility at CERN.

scholarly journals Nuclear electric-quadrupole interaction of ion-implantedHg203andZn69min graphite

1992 ◽  
Vol 46 (14) ◽  
pp. 8818-8827 ◽  
Author(s):  
B. Kastelein ◽  
M. W. J. Prins ◽  
J. Andriessen ◽  
H. Postma ◽  
L. Klostermann ◽  
...  
Keyword(s):  
Quadrupole Interaction ◽  
Electric Quadrupole ◽  
Electric Quadrupole Interaction

Electric quadrupole interaction at181Ta in RNi5 compounds

1985 ◽  
Vol 23 (1) ◽  
pp. 89-102 ◽  
Author(s):  
M. B. Kurup ◽  
K. G. Prasad ◽  
K. Raghunathan ◽  
R. P. Sharma
Keyword(s):  
Quadrupole Interaction ◽  
Electric Quadrupole ◽  
Electric Quadrupole Interaction

Electric quadrupole interaction of111Cd in the semiconductor CdSe

1981 ◽  
Vol 10 (1-4) ◽  
pp. 963-966 ◽  
Author(s):  
H. Barfu� ◽  
G. B�hnlein ◽  
H. Hohenstein ◽  
W. Kreische ◽  
H. Niedrig ◽  
...  
Keyword(s):  
Quadrupole Interaction ◽  
Electric Quadrupole ◽  
Electric Quadrupole Interaction
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