Investigation of copper minerals by NQR: Crystallochemistry, electronic structure, lattice dynamics

Abdullin, R. S.; Kal’chev, V. P.; Pen’kov, I. N.

doi:10.1007/bf00307991

Cited by 25 publications

(16 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect is related to the increased occupation of the 3d shell forced by the orbital potential, which makes the charge distribution of the 3d shell more spherical, when accommodating an increased number of electrons. The GGA calculations result in an EFG of about −5 ϫ 10 21 V / m 2 , which is only half of the experimental value of 10.6ϫ 10 21 V / m 2 ͑only the magnitude of the EFG can be measured͒ 34. However, with GGA+ U and a large U eff equal to 13.6 eV the calculated value ͑−10ϫ 10 21 V / m 2 ͒ comes close to the experimental EFG.Considering our results it is rather clear that the GGA + U method improves the electronic structure compared to calculations with GGA only.…”

mentioning

confidence: 85%

Strong excitonic effects inCuAlO2delafossite transparent conductive oxides

et al. 2009

View full text Add to dashboard Cite

The imaginary part of the dielectric function of CuAlO 2 has been calculated including the electron-hole correlation effects within Bethe-Salpeter formalism ͑BSE͒. In the initial step of the BSE solver the band structure was calculated within density-functional theory plus an orbital field ͑LDA/ GGA+ U͒ acting on Cu atoms. We discuss the influence of the strength of the additional orbital field on the band structure, electric field gradients, and the dielectric function. The calculated dielectric function shows very strong electron-hole correlation effects manifested with large binding energies of the lowest excitons. The electron-hole pair for the lowest excitations are very strongly localized at a single Cu plane and confined within only a few neighboring shells.

show abstract

mentioning

confidence: 85%

Strong excitonic effects inCuAlO2delafossite transparent conductive oxides

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Earlier studies of copper sulphides and oxides [6] have shown that the lattice contribution to the EFG is the dominant for monovalent copper. Taking Ÿ -13.8 [7], the calculated value of the lattice contribution to the 63Cu NQR frequency appeared to be equal to 2.3 MHz, about two times less than the observed one.…”

Section: Nqr Frequenciesmentioning

confidence: 99%

Electronic structure and lattice dynamics of domeykite Cu3As according to nuclear quadrupolar resonance of75As and63,65Cu

et al. 2002

View full text Add to dashboard Cite

The temperature dependences of nuclear quadrupole resonance (NQR) frequencies, the line width and nuclear relaxation of 75As and 63'65Cu, as well as the electrical resistivity in domeykite Cu3As are studied in the temperature range of 4.2-300 K. The comparison of the calculated with the rneasured lattice contribution to the NQR frequencies points at a substantial role played by the conduction electrons in creating the electric field gradient at the nuclei sites. The temperature dependence of the copper and arsenic nuclear spin-lattice relaxation linear at 4.2 < T < 200 K and that of the electric resistivity (30 < T < 200 K) prove the metallic character of the conductivity of domeykite. The enhancement of nuclear relaxation, the narrowing of copper and arsenic NQR line widths are considered as arising due to the ionic movement starting beyond 200 K. This movement influences the etectric resistivity, most likely due to the inreasing density of states at the Fermi surface.

show abstract

“…The 63,65 Сu NMR spectrum in a local field for samples of chalcopyrite (CuFeS 2 ) mineral was investigated in [3,4] at temperatures 77-300 K. It comprised six resonant lines and was formed by two widespread copper isotopes ( 63 Cu and 65 Cu) existing in the location of resonant nuclei in a local magnetic field of ~1.6 T. The spectrum of each copper isotope had three resonant lines (nuclear spins of both isotopes were I = 3/2) and consisted of the central line and two quadrupole satellites (Fig. 1a).…”

Section: Resultsmentioning

confidence: 99%

63,65Cu NMR Method in a Local Field for Investigation of Copper Ore Concentrates

Гавриленко

Старых²,

Khabibullin

et al. 2015

Russ Phys J

View full text Add to dashboard Cite

To choose the most efficient method and ore beneficiation flow diagram, it is important to know physical and chemical properties of ore concentrates. The feasibility of application of the 63,65 Cu nuclear magnetic resonance (NMR) method in a local field aimed at studying the properties of copper ore concentrates in the copper-iron-sulfur system is demonstrated. 63,65 Cu NMR spectrum is measured in a local field for a copper concentrate sample and relaxation parameters (times T 1 and T 2 ) are obtained. The spectrum obtained was used to identify a mineral (chalcopyrite) contained in the concentrate. Based on the experimental data, comparative characteristics of natural chalcopyrite and beneficiated copper concentrate are given. The feasibility of application of the NMR method in a local field to explore mineral deposits is analyzed.

show abstract

Investigation of copper minerals by NQR: Crystallochemistry, electronic structure, lattice dynamics

Cited by 25 publications

References 10 publications

Strong excitonic effects inCuAlO2delafossite transparent conductive oxides

Strong excitonic effects inCuAlO2delafossite transparent conductive oxides

Electronic structure and lattice dynamics of domeykite Cu3As according to nuclear quadrupolar resonance of75As and63,65Cu

63,65Cu NMR Method in a Local Field for Investigation of Copper Ore Concentrates

Contact Info

Product

Resources

About