Electronic and elastic properties of yttrium gallium garnet under pressure from <i>ab initio</i> studies

Monteseguro, V.; Rodríguez‐Hernández, P.; Lavı́n, V.; Manjón, F. J.; Múñoz, A.

doi:10.1063/1.4804133

Cited by 20 publications

(28 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this position, and due to the ionic size considerations, the RE 3+ ions are expected to predominantly enter in the structure replacing the Y 3+ ions. Moreover, the vibrational modes and the optical properties of the RE 3+ ions in these nano-garnets are also quite similar to those found in the YGG bulk crystal [19][20][21] . The visible and NIR diffuse reflectance spectrum in the range from 200 to 1800 nm was measured using a spectrophotometer with an integrating sphere (Agilent Cary 5000).…”

Section: Ba Experimentalsupporting

confidence: 64%

“…Moreover, a careful calibration for the biological range (292-335 K) has been also carried out. Since the concentration of optically active ions affects the sensitivity of the optical sensor in bulk matrices 20 , this work will also explore whether this effect also occurs in the YGG nano-garnets. Finally, the behavior of the green emissions with temperature is analyzed as a function of the exciting laser wavelength by choosing a blue laser radiation at 488 nm and a nearinfrared (NIR) laser at 800 nm.…”

Section: A Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets

et al. 2014

Self Cite

View full text Add to dashboard Cite

The temperature-dependent green luminescence of Y 3 Ga 5 O 12 nano-garnets doped with different concentrations of Er 3+ ions has been measured from 300 to 850 K and, in more detail, in the biological range from 292 to 335 K. The green emissions were obtained exciting both under 488 nm blue or 800 nm near-infrared laser radiations. Both excitations give rise to bright green luminescence that can be seen by the naked eyes, and which can be associated either with Stokes processes, i.e. multiphonon relaxations followed by green spontaneous emission, in the former case or with infrared-to-visible upconversion processes in the latter one. The temperature-induced changes in the Er 3+ green emissions have been calibrated for both excitations and results point to a strong dependence on the concentration of optically active Er 3+ ions. The maximum value of the thermal sensitivity, 64 x 10 -4 K -1 at 547 K, has been obtained for the nano-garnets doped with the lowest concentration of Er 3+ ions, being one of the highest values found in the literature. These results allow concluding that a relatively low concentration of optically active ions is advisable and the changes induced by temperature on the green emissions are independent of the laser excitation radiation used, necessary to calibrate the temperature of the immediate environment of the Er 3+ -doped Y 3 Ga 5 O 12 nano-garnets.has been shown that the behavior of the green luminescence with the temperature is independent of the laser excitation wavelength, blue or near-infrared, used, although the latter is more suitable for biomedical applications.

show abstract

Section: Ba Experimentalsupporting

confidence: 64%

Section: A Introductionmentioning

confidence: 99%

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…C 11 is higher than C 44 , indicating that in this material the resistance to a shear deformation is weaker than the resistance to a compression. 12 Therefore, our results for LuGG are in good agreement with the reported experimental data for other gallium garnets and suggest that LuGG will become amorphous at around 87 GPa. 4.…”

Section: Elastic Propertiessupporting

confidence: 90%

“…Besides, since phonons play an important role in the electrical, thermal and optical properties of materials it is essential to study their lattice dynamics to go deeper into the physics of these materials. 12 Now we are interested in studying similar effects in our system, to evaluate the modifications related to the possible effect of the ''chemical pressure'' related to size effects when changing Y with a Lu atom. 5 The knowledge of the evolution of the elastic properties and the lattice dynamics of garnets under pressure could allow understanding possible changes occurring in the solid-state properties of the garnet and how they would affect the environment and, hence, the luminescence properties of RE 3+ at high pressures.…”

Section: Introductionmentioning

confidence: 99%

Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure

Monteseguro

Rodríguez‐Hernández

Ortiz

et al. 2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

An ab initio study of the structural, elastic and vibrational properties of the lutetium gallium garnet (Lu3Ga5O12) under pressure has been performed in the framework of the density functional theory, up to 95 GPa. Pressure dependence of the elastic constants and the mechanical stability are analyzed, showing that the garnet structure is mechanically unstable above 87 GPa. Lattice-dynamics calculations in bulk at different pressures have been performed and compared with Raman scattering measurements of the nanocrystalline Tm(3+)-doped Lu3Ga5O12 up to 60 GPa. The theoretical frequencies and pressure coefficients of the Raman active modes for bulk Lu3Ga5O12 are in good agreement with the experimental data measured for the nano-crystals. The contributions of the different atoms to the vibrational modes have been analyzed based on the calculated total and partial phonon density of states. The vibrational modes have been discussed in relation to the internal and external modes of the GaO4 tetrahedron and the GaO6 octahedron. The calculated infrared modes and their pressure dependence are also reported. Our results show that with this nano-garnet size the sample has essentially bulk properties.

show abstract

“…In addition, this is the similar lattice disorder case for the substitution of divalent and trivalent cations in henritermierite [16] and pyrope and grossular [17]. The electronic properties of garnet series which are influenced by the structural distortion are worth of investigating carefully [14] [18][19][20][21]. Cano et al showed that grossular has a direct band gap of 5.22 eV [14].…”

Section: Introductionmentioning

confidence: 95%

Crystal structure and band gap studies of hydrogarnet calculated results by density functional theory

Pan¹,

Chao²,

Ke³

2016

Proceedings of the 2016 6th International Conference on Machinery, Materials, Environment, Biotechnology and Computer

View full text Add to dashboard Cite

Herein, we investigate the hydrogarnet sample by X-ray diffraction and calculated the related garnets included grossular, katoite and hydrogrossular by density functional theory to investigate the effect of silicon composition. The results of X-ray diffraction suggests that the chemical formula should be C a2.93 Al 1.97 Si 0.64 O 2.56 (OH) 9.44. The optimized lattice parameters are in good agreement with the available data. We demonstrated the structural details of oxygen tetrahedron with or without silicon and found the stability and the band gap of garnet to be selectively modified by controlling the distribution and concentration of silicon atoms at different structural deformation levels. Moreover, the hydrogrossular configuration with the silicon atoms in separate manner is favored of the high stability and large band gap. It is firstly proposed that the band gap of hydrogarnet should be 3.17-3.65 eV by first-principles calculations. This was explained by the majority of the DOS contributions from the electrons in O and Ca atoms. It is believed that our research contributes to the mechanism of silicon distribution in garnet and helps the further disposal and treatment of silicate mud.

show abstract

Electronic and elastic properties of yttrium gallium garnet under pressure from ab initio studies

Cited by 20 publications

References 35 publications

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets

Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure

Crystal structure and band gap studies of hydrogarnet calculated results by density functional theory

Contact Info

Product

Resources

About

Electronic and elastic properties of yttrium gallium garnet under pressure from ab initio studies

Cited by 20 publications

References 35 publications

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er3+ ions in Y3Ga5O12 nano-garnets

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er3+ ions in Y3Ga5O12 nano-garnets

Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure

Crystal structure and band gap studies of hydrogarnet calculated results by density functional theory

Contact Info

Product

Resources

About

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets

Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er³⁺ ions in Y₃Ga₅O₁₂ nano-garnets