Journal of molecular structure, 83 1982 1 7 1 elsevier scientific publishing company, amsterdam printed in the netherlands nuclear quadrupole resonance spectra database h. The resonance effect comes from the fact that valence electrons preferentially align with some of the 14 n. Many nuclei with spins greater than vz have a quadrupole moment and most of these quadrupole moments have been measured and tabulated. Instead, nqr exploits the fact that some nuclei possess an electric quadrupole moment, which can be thought of as arising from two backtoback electric dipoles positive and. By emission or absorption of radiation from the nucleus information of the local structure is obtained, as an interaction of an atom with its closest neighbours. Nuclear quadrupole resonances in compact vapor cells. Research laboratory nrl has expertise in solid state nuclear mag netic resonance nmr. Nuclei with a spin greater than 12, such as 14 n, have a nuclear electric quadrupole moment that interacts with the electric field of the surrounding electrons, producing an electric quadrupole coupling. Table of nuclear magnetic dipole and electric quadrupole moments n.
The nuclei that show nqr spectra are listed and the. Nmr references for quadrupole hamiltonian pascalman. Temperature effects in nuclear quadrupole resonance. High sensitivity nuclear quadrupole resonance of light nuclei. Some examples of nuclear quadrupole moments nucleus i q 1028m2 2h 1 2. Nuclear magnetic resonance nmr and nqr phenomena are caused by applying radiofrequency wave having. A coil antenna being used to detect the signal from the sample right 3.
How weak rf pulses and double resonance crossrelaxation contribute to explosives detection. This table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Nuclear quadrupole resonance nqr the resonance absorption of electromagnetic energy in a crystal owing to transitions between energy levels that are formed as a result of the interaction of nuclei that have an electric quadrupole moment with the crystal electric field. Feasibility of nuclear quadrupole resonance as a technique for detecting personborne explosives michael l. Nuclear quadrupole resonance how is nuclear quadrupole. Nuclear magnetic resonance, first demonstrated in 1946, takes advantage of the fact that certain atomic nuclei possess magnetic dipole moments. Nuclear quadrupole resonance nqr spectroscopy wulfsberg. Stone, oxford physics, clarendon laboratory parks road, oxford ox1 3pu u. Locked nuclear quadrupole resonance spectrometer for pressure. Nuclear m agnetic resonance sp ectroscopy nuc lear quadrupole resonance applications theory offered townes and dailey. Chihara department of chemistry, faculty of science, osaka university, toyonaka 560 and japan association for international chemical information jaici, 216 yayoi, bunkyoku, tokyo 1, japan abstract a computer. Nuclear quadrupole resonance for explosive detection hideo itozaki and go ota graduate school of engineering science, osaka university machikaneyama toyonaka, osaka, 5608531, japan abstract abstract a nuclear quadrupole resonance detector has been developed. Nuclear quadrupole resonance spectra database sciencedirect.
Ab initiocalculations of nuclear quadrupole resonance frequencies. Nuclear quadrupole resonance for explosive detection. View nuclear quadrupole resonance research papers on academia. Table of nuclear magnetic dipole and electric quadrupole. Nuclear quadrupole resonance nqr is a radio frequency rf spectroscopy technique for solid materials the instrumentation is like nmr but nqr doesnt require an applied b 0 field because the physical mechanism is different there are benefits and drawbacks to nqr as compared with nmr. However, despite the great similarities between nmr and nuclear quadrupole resonance nqr, no experimental implementation for qip using nqr has been reported. Nuclear quadrupole resonance spectroscopy springerlink. Nuclear pure quadrupole resonance nqr is a resonance technique that provides distinctly different information from that provided by nuclear magnetic resonance nmr. These include studies of molecular structure in the solid state. Pdf role of spin state on the geometry and nuclear.
The three energy levels of 14n and corresponding transition frequencies left 2. A modification of nuclear quadrupole double resonance with coupled multiplet is proposed which can be used for the measurement of the dipolar structure of the 17o nuclear quadrupole resonance. Nuclear magnetic resonance, first demonstrated in 1946, takes advan tage of the fact that certain atomic nu clei possess magnetic dipole moments that is. Recent developments in solidstate nuclear magnetic resonance. Vanderhart institute for materials research, national bureau of standards, washington, d. Bryce solidstate nuclear magnetic resonance and nuclear quadrupole resonance as complementary tools to study quadrupolar nuclei in solids, concepts magn.
Pdf nuclear quadrupole resonance, applications researchgate. Nuclear quadrupole resonance nqr and nuclear magnetic resonance nmr studies on sup 63,65cu have demonstrated the the resonance properties of these nuclei can give important information about the electronic structure of the high temperature superconductor ybasub 2cusub 3osub 7minusx as well as the exchange coupling energy between the cu2 sites. Role of spin state on the geometry and nuclear quadrupole resonance parameters in hemin complex. Electric field gradient nuclear quadrupole resonance double resonance nitrogen mustard asymmetry factor these keywords were added by machine and not by the authors. Nuclear quadrupole resonance nqr is the study of the energy splittings due to interaction of the electric quadrupole moment of the nucleus with the electric field gradient that exists at the nuclear site. Among these is nitrogen14 14n and nitrogen is a constituent of explosives used in landmines, such as rdx and tnt.
This moment is a measure of how the nuclear charge distribution deviates away from spherical symmetry and it happens in nuclei with greater spin or equal to. Here viiand ye are the resonance frequencies when the electronic magnetic moment is in a direction parallel and perpendicular to the caxis respectively, 0 the angle between the magnetic moment and the caxis, q the principal value of the e. Nuclear quadrupole resonance as a nondestructive testing tool. Journal of research of the national bureau of standards. In the simplest case, for example, 35cl in solid cl 2, nqr is associated with the precession of the angular. Temperature effects in nuclear quadrupole resonance spectroscopy. Paul alan, a nuclear quadrupole resonance study of heavy transition metal halide compounds with bridging halogen atoms 1972. The quadrupole moment, nonzero only for nuclei with spin quantum number i greater than or equal to 1, is a nuclear.
Nuclear quadrupole resonance nqr article about nuclear. Nuclear quadrupole resonance nqr, a derivative of nuclear magnetic resonance nmr, is a bulk inspection technology which can be used to detect certain chemical elements which have an electric quadrupole moment. Nuclear quadrupole resonance in amorphous semiconductors in. Nuclear magnetic resonance nmr spectroscopy direct observation of the hs and cs of a molecules nuclei are positively charged and spin on an axis. Calculation of the nuclear quadrupole resonance spectra of. In nmr the splitting of the energy levels, and therefore the frequency observed, occurs because of the interaction of the nuclear magnetic moment with an external magnetic field. Nuclear quadrupole resonance nqr uses radiofrequency rf magnetic fields to induce and detect transitions between sublevels of a nuclear ground state, a description that also applies to nuclear magnetic resonance nmr. Table of nuclear magnetic dipole and electric quadrupole moments. Nuclear magnetic resonance nmr has been widely used in the context of quantum information processing qip. The polymer diagnostics section code 6122 of the u.
Locked nuclear quadrupole resonance spectrometer for pressure measurements ronald c. Nuclear spectroscopy is a superordinate concept of methods that uses properties of a nucleus to probe material properties. Nuclear quadrupole resonance has much in common with nuclear magnetic resonance nmr, the fundamental physical process that makes magnetic resonance imaging possible. Abstract the article concerns the usefulness of nuclear quadrupole resonance nqr spectroscopy in inorganic and organometallic chemistry.
Encyclopedia of spectroscopy and spectrometry, edition. Nuclear quadrupole resonance spectroscopy or nqr is a chemical analysis technique related to nuclear magnetic resonance. Nuclear quadrupole resonance is similar in concept, but unlike nmr it does not rely on the nuclei aligning themselves in an externally applied magnetic field. A nuclear quadrupole resonance study of heavy transition. If the inline pdf is not rendering correctly, you can download the pdf file here. A selective absorption phenomenon observable in a wide variety of polycrystalline compounds containing nonspherical atomic nuclei when placed in a magnetic radiofrequency field. Pdf the theory of nuclear quadrupole resonance spectroscopy is summarized. The gradient of an electrical field in a place of a presence. Nuclear quadrupole resonance nqr is the study of the energy splittings due to interaction of the elec tric quadrupole moment of the nucleus with the elec.
The sensitivity of the slusher and hahns nuclear quadrupole double resonance technique is calculated in general for an arbitrary nuclear spin s of the quadrupole nuclei and for an arbitrary asymmetry parameter eta of the electric field gradient tensor. This process is experimental and the keywords may be updated as the learning algorithm improves. Feasibility of nuclear quadrupole resonance as a technique. Nuclear quadrupole resonance article about nuclear.
They performed a detailed perturbationnqr regime, where little or. Ab initio calculations of nuclear quadrupole resonance. Pdf the applications of nuclear quadrupole resonance nqr are surveyed. Nuclear quadrupole resonance research papers academia.739 1558 183 630 251 948 1167 1480 1116 173 636 1614 26 56 789 1207 1248 856 540 1474 190 1005 954 1074 1409 111 272 814 1387 402 1248 1343 443 1250 470 981 1019 1230 893 48 1194