27Al nuclear magnetic resonance studies of the Y3-xLuxAl5O12mixed garnets

Charnaya, E. V.; Tien, Cheng; Lu, J. J.; Wu, Ru‐Rong; Иванов, С. Н.; Хазанов, Е. Н.

doi:10.1088/0953-8984/13/39/306

Cited by 13 publications

(5 citation statements)

References 17 publications

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“…The 27 Al MAS spectra obtained for the pure yttrium aluminum garnet were similar to those published earlier [8][9][10]. For the octahedral site, one can see the central line and all sidebands corresponding to satellite transitions (AE1/2 $ AE3/2 and AE3/2 $ AE5/2), while for the tetrahedral site only the central line and several near sidebands are observable because of stronger quadrupole coupling for this site (Fig.…”

Section: Resultssupporting

confidence: 84%

“…The spectra can be well fitted with the parameters listed in Table 1 when the asymmetry parameter is assumed to be equal to 0. The chemical shifts were similar to those measured in [8][9][10]. The chemical shifts were similar to those measured in [8][9][10].…”

Section: Resultssupporting

confidence: 82%

“…1). The nuclear quadrupole coupling constants, e 2 qQ/h [4] (e is the electron charge, eq is the zz component of the electric field gradient tensor, Q is the nuclear quadrupole moment, and h is the Planck constant), were the same within the experimental accuracy as in [8][9][10][11][12][13] for both tetrahedral and octahedral sites. The nuclear quadrupole coupling constants, e 2 qQ/h [4] (e is the electron charge, eq is the zz component of the electric field gradient tensor, Q is the nuclear quadrupole moment, and h is the Planck constant), were the same within the experimental accuracy as in [8][9][10][11][12][13] for both tetrahedral and octahedral sites.…”

Section: Resultsmentioning

confidence: 87%

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27Al and45Sc NMR Studies of the Y3ScxAl5?xO12 Mixed Garnets

Tien¹,

Charnaya²,

Sun³

et al. 2002

phys. stat. sol. (b)

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The substitution of aluminum with scandium in the mixed yttrium aluminum scandium garnets, Y 3 Sc x Al 5--x O 12 (x ¼ 0, 0.05, 0.5, 1.5), was studied for the first time using 27 Al magic angle spinning (MAS), multiple quantum (MQ) MAS NMR, and 45 Sc MAS NMR. The aluminum and scandium quadrupole coupling constants and isotropic chemical shifts were evaluated for all garnets under study. 27 Al 2D spectra evidenced variation of the isotropic shifts over the aluminum sites in the mixed garnets.

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Section: Resultssupporting

confidence: 84%

Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 87%

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27Al and45Sc NMR Studies of the Y3ScxAl5?xO12 Mixed Garnets

Tien¹,

Charnaya²,

Sun³

et al. 2002

phys. stat. sol. (b)

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“…In accordance with the previous studies [29,35,36], 27 Al MAS NMR allows easy separation of spectral lines from Al ions in the tetrahedral and octahedral positions of garnet structure. 27 Al MAS NMR spectra of Lu3GaxAl5-xO12:Ce single crystals obtained with the spinning rate of 22 KHz are presented in Fig.…”

Section: Nmr Investigation Of Ga and Al Distribution In Lu3gaxal5-xo1...supporting

confidence: 85%

Influence of gallium content on Ga3+ position and photo- and thermally stimulated luminescence in Ce3+-doped multicomponent (Y,Lu)3GaxAl5-xO12 garnets

Babin

Buryi

Chlan

et al. 2018

Journal of Luminescence

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Photoluminescence, thermally stimulated luminescence (TSL) and EPR characteristics of the Ce 3+ -doped single crystals of multicomponent Y1Lu2GaxAl5-xO12 and Lu3GaxAl5-xO12 garnets with different Ga contents (x = 0, 1, 2, 3, 4, 5) excited in the Ce 3+ -related absorption bands are investigated in the 9 -500 K temperature range. The distribution of Ga 3+ and Al 3+ ions in the crystal lattice is determined by the NMR method. The relative number of Ga 3+ ions in the tetrahedral crystal lattice sites, the maxima positions of the TSL glow curve peaks and the corresponding trap depths are found to decrease linearly with the increasing Ga content. At the same time, the reduction of the activation energy Ea of the TSL glow curve peaks creation under irradiation in the 4f -5d1 absorption band of Ce 3+ is strongly nonlinear. To explain this effect, the suggestion is made that Ea is the energy distance between the excited 5d1 level of Ce 3+ and a defect level located between the 5d1 level and the bottom of the conduction band and arising from the Ga 3+ ion perturbed by the nearest neighboring Ce 3+ ion. The electrons thermally released from the excited Ce 3+ ions are suggested to be trapped at the perturbed Ga 3+ ions resulting in the appearance of electron Ga 2+ centers. In spite of the fact that the paramagnetic Ga 2+ ions were not detected by EPR, the described above process was found for Fe 3+ impurity ions, namely the electron transfer from the 5d1 excited levels of Ce 3+ to Fe 3+ was directly detected by EPR.

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“…yttrium aluminium garnet or YAG) are also important in solid state lasers and other technologies. 38 A number of single crystal (primarily 27 Al) NMR studied have been made on garnets, some of which have described large line splittings due to unpaired electron-nuclear dipolar interactions, which are strongly orientation-dependent, but which are expected to be averaged to zero by rapid magic-angle spinning. 39,40 Most silicate garnets have cubic symmetry and a simple structure that can make them especially interesting as case studies in spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Anomalous resonances in 29Si and 27Al NMR spectra of pyrope ([Mg,Fe]3Al2Si3O12) garnets: effects of paramagnetic cations

Stebbins

Kelsey

2009

Phys. Chem. Chem. Phys.

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In oxide and silicate materials, particularly naturally-occurring minerals with contents of iron oxides greater than a few percent, paramagnetic impurities are well-known to broaden MAS NMR peaks, decrease relaxation times, and even cause overall loss of signal intensity. However, detection of resolved, discrete peaks that are shifted in frequency by nearby unpaired electron spins is rare in such systems. We report here high-resolution (27)Al and (29)Si spectra for synthetic and natural samples of pyrope garnet ([Mg,Fe](3)Al(2)Si(3)O(12)), the latter containing up to 3.5 wt% FeO. For both nuclides, spectra contain anomalous NMR peaks at frequencies that are 25 to 200 ppm from normal ranges, possibly through pseudocontact shifts induced by paramagnetic cations. Quantitation of peak areas suggests that signals from nuclides with such cations in their first shell may be broadened enough to be unobservable, while those with paramagnetics in their second cation shells may be substantially shifted. Overall spin-lattice relaxation rates are greatly enhanced by such impurities, and shifted resonances relax much faster than the unshifted main peaks. A high symmetry crystal structure (in this case cubic), which limits the number of different cation-cation distances in each shell, combined with a relatively low (non-cubic) symmetry for the sites hosting the magnetic cations, may be needed to readily detect such features.

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²⁷Al nuclear magnetic resonance studies of the Y_3-xLu_xAl₅O₁₂mixed garnets

Cited by 13 publications

References 17 publications

27Al and45Sc NMR Studies of the Y3ScxAl5?xO12 Mixed Garnets

27Al and45Sc NMR Studies of the Y3ScxAl5?xO12 Mixed Garnets

Influence of gallium content on Ga3+ position and photo- and thermally stimulated luminescence in Ce3+-doped multicomponent (Y,Lu)3GaxAl5-xO12 garnets

Anomalous resonances in 29Si and 27Al NMR spectra of pyrope ([Mg,Fe]3Al2Si3O12) garnets: effects of paramagnetic cations

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