Nuclear acoustic resonance in metals and alloys: A review

Sundfors, R. K.; Bolef, D. I.; Fedders, Peter A.

doi:10.1007/bf02043303

Cited by 12 publications

(5 citation statements)

References 99 publications

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“…Contributions from outside the atomic sphere were negligibly small. This is in accordance to the prediction of a strong contribution of conduction electrons based on calculations with a point-charge model ( [11] and citations therein) and, in a more general way, to the origin of the EFG in hexagonal closed packed (hcp) metals [55]. The ratio between p and d state contributions was found to be different for the distinct strains ε zz and γ yz but usually dominated by p states.…”

Section: Discussionsupporting

confidence: 90%

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Determination of gradient elastic tensors: stress and strain dependencies of electric field gradients in cubic and hexagonal systems

Brüsewitz

Vetter

Hofsäss

2015

J. Phys.: Condens. Matter

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We present ab-initio calculations of the independent components of gradient elastic tensors, so-called gradient elastic constants, which relate electric field gradient tensors to stress or strain tensors. The constants of cubic and hexagonal metals, MAX phases, and zinc oxide were determined within the framework of density functional theory by using the augmented plane waves plus local orbitals method implemented in the WIEN2k code. Comparison with experimental gradient elastic constants and electric field gradients' stress dependencies suggest an accuracy of about 30% of the calculated constants, independent of the probe that detects the field gradient being self- or foreign-atom. Changes in the electric field gradient take place by strain-induced asymmetric occupations of the p and d states in the valence region for all investigated materials. Volume and structural dependencies of the electric field gradient can directly be determined from this fundamental approach and are, for hexagonal closed packed metals, consistent with vanishing electric field gradients around ideal close packing and volume dependencies larger than one. The concept of these calculations is applicable in any hyperfine interaction method and, thus, can be used to gain information about intrinsic strains in systems where the experimental gradient elastic constants are inaccessible.

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Section: Discussionsupporting

confidence: 90%

“…Over the last decades, gradient elastic constants have been directly measured in cubic systems by means of nuclear magnetic resonance spectroscopy (NMR) [3,4], nuclear acoustic resonance (NAR) [5][6][7][8][9][10][11] or, partly, in hexagonal systems by perturbed angular correlation spectroscopy (PAC) [2,12].…”

Section: Introductionmentioning

confidence: 99%

Determination of gradient elastic tensors: stress and strain dependencies of electric field gradients in cubic and hexagonal systems

Brüsewitz

Vetter

Hofsäss

2015

J. Phys.: Condens. Matter

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“…At room temperature, the effect is trivial, but it can be dominant if acoustic energy is introduced into the system at significant power levels, where, the nuclei subjected to an external magnetic field, absorb acoustic waves. The phenomenon is mainly observed in metals, for example, it was initially observed in the context of aluminum 26 . In metals, the dominant mechanism of coupling is time varying electric field gradient generated by ultrasonic wave and dynamic dipolar interaction, where acoustic waves induce microscopic currents and time varying radio frequency magnetic fields, which interact with magnetic dipole moments 27 .…”

Section: Introductionmentioning

confidence: 99%

Generation of acoustic-Brownian noise in nuclear magnetic resonance under non-equilibrium thermal fluctuations

Sinha

2020

Sci Rep

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We present an analytical study on generation of acoustic-Brownian noise in nuclear magnetic resonance (NMR) induced as a result of thermal fluctuations of the magnetic moments under non-equilibrium thermal interactions which has not been explored independent of Nyquist–Johnson noise until now. The mechanism of physical coupling between non-equilibrium thermal fluctuations and magnetic moments is illustrated using Lighthill’s formulation on suspension dynamics. We discover that unlike Nyquist–Johnson noise which has a uniform spectral density across a range of frequencies, the spectral dependence of acoustic-Brownian noise decreases with an increase in frequency and resembles Brownian noise associated with a particle in a potential well. The results have applications in the field of image enhancement algorithm as well as noise reduction instrumentation in NMR systems.

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“…The proposed approach offers a new mechanism of nuclear surface acoustic resonance (NSAR), distinguishing itself from well known nuclear acoustic resonance (NAR) in bulk materials [12], where the nuclear spins interact with acoustic waves through the dynamic electrical quadrupole coupling [13] or dynamic Alpher-Rubin coupling [14]. The Barnett field induced by the SAW cavity can be confined in a volume far smaller than the size of the coil used in the conventional NMR experiments [15].…”

mentioning

confidence: 99%

Nuclear Surface Acoustic Resonance with Spin-Rotation Coupling

Usami,

Takeda

2020

Preprint

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We show that, under an appropriate out-of-plane static magnetic field, nuclear spins in a thin specimen on a surface acoustic wave (SAW) cavity can be resonantly excited and detected through spin-rotation coupling. Since such a SAW cavity can have the quality factor as high as 10 4 and the mode volume as small as 10 −2 mm 3 the signal-to-noise ratio in detecting the resonance is estimated to be quite high. We argue that detecting nuclear spin resonance of a single flake of an atomically-thin layer of two-dimensional semiconductor, which has so far been beyond hope with the conventional inductive method, can be a realistic target with the proposed scheme.

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Nuclear acoustic resonance in metals and alloys: A review

Cited by 12 publications

References 99 publications

Determination of gradient elastic tensors: stress and strain dependencies of electric field gradients in cubic and hexagonal systems

Determination of gradient elastic tensors: stress and strain dependencies of electric field gradients in cubic and hexagonal systems

Generation of acoustic-Brownian noise in nuclear magnetic resonance under non-equilibrium thermal fluctuations

Nuclear Surface Acoustic Resonance with Spin-Rotation Coupling

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