Elastic constants of synthetic single crystal corundum

Tefft, Wayne E.

doi:10.6028/jres.070a.024

Cited by 100 publications

(33 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, for Al 2 O 3 [1210], we calculate that ν = 0.0805 [42][43][44] and, thus, flat / free ≈ 1. In this way, can be obtained from a modified Stoney's formula [45] …”

Section: Cantilever Technique and Mel Constant M 2 γ2mentioning

confidence: 97%

See 1 more Smart Citation

In-plane uniaxial magnetic anisotropy induced by anisotropic strain relaxation in high lattice-mismatched Dy/Sc superlattices

2014

View full text Add to dashboard Cite

We report on the magnetic and structural characterization of high lattice-mismatched [Dy 2nm /Sc t Sc ] superlattices, with variable Sc thickness t Sc = 2-6 nm. We find that the characteristic in-plane effective hexagonal magnetic anisotropy K 6,ef 6 reverses sign and undergoes a dramatic reduction, attaining values of ≈13-24 kJm −3 , when compared to K 6 6 = −0.76 MJm −3 in bulk Dy. As a result, the basal plane magnetic anisotropy is dominated by a uniaxial magnetic anisotropy (UMA) unfound in bulk Dy, which amounts to ≈175-142 kJm −3 . We attribute the large downsizing in K 6,ef 6 to the compression epitaxial strain, which generates a competing sixfold magnetoelastic (MEL) contribution to the magnetocrystalline (strain-free) magnetic anisotropy. Our study proves that the in-plane UMA is caused by the coupling between a giant symmetry-breaking MEL constant M 2 γ,2 ≈ 1 GPa and a morphic orthorhombiclike strain ε γ,1 ≈ 10 −4 , whose origin resides on the arising of an in-plane anisotropic strain relaxation process of the pseudoepitaxial registry between the nonmagnetic bottom layers in the superstructure. This investigation shows a broader perspective on the crucial role played by epitaxial strains at engineering the magnetic anisotropy in multilayers.

show abstract

“…In this case, for Al 2 O 3 [1210], we calculate that ν = 0.0805 [42][43][44] and, thus, flat / free ≈ 1. In this way, can be obtained from a modified Stoney's formula [45] …”

Section: Cantilever Technique and Mel Constant M 2 γ2mentioning

confidence: 97%

“…Finally, in Eq. (8), C xx is considered temperature independent [42][43][44] and the room temperature value is typically used.…”

Section: Cantilever Technique and Mel Constant M 2 γ2mentioning

confidence: 99%

In-plane uniaxial magnetic anisotropy induced by anisotropic strain relaxation in high lattice-mismatched Dy/Sc superlattices

2014

View full text Add to dashboard Cite

show abstract

“…Strain components of sapphire are calculated as functions of the uniaxial stress ͑P͒ by Hook's law by taking elastic compliances of sapphire as S 11 ϭ2.33ϫ10 Ϫ12 m 2 /N, S 12 ϭϪ6.93ϫ10 Ϫ13 m 2 /N. 7 Thus, strain components in GaN induced by the applied stress can be estimated from the strain in sapphire because in-plane deformation of GaN is forced by the deformation of sapphire. It should be noted that the residual strain in the GaN film without applied stress is estimated as ⑀ zz ϭ0.011 by comparing the photoluminescence ͑PL͒ peak energy of the film with reported results in Refs.…”

Section: Reflectance Spectroscopy On Gan Films Under Uniaxial Stressmentioning

confidence: 99%

Reflectance spectroscopy on GaN films under uniaxial stress

Yamaguchi

Mochizuki

Sasaoka

et al. 1997

Applied Physics Letters

View full text Add to dashboard Cite

The uniaxial stress effects on valence band structures in GaN are investigated by reflectance spectroscopy. It is observed that the energy separation between A and B valence bands increases with the application of uniaxial stress in the c plane. The experimental results are analyzed on the basis of the k⋅p theory, and deformation potential D5 is determined as −3.3 eV. It is indicated that the uniaxial strain effect could be utilized for improving GaN-based laser performance.

show abstract

“…For the backward integrations, elastic sapphire is modeled as hydrodynamic (no strength) using the Mie-Grüneisen EOS referenced to the elastic Hugoniot of Barker and Hollenbach (1970), with Γ 0 =1.5. Thermal softening of the sapphire elastic constants causes at most a 1% change in longitudinal modulus for the temperatures of interest [Tefft, 1966], and was therefore neglected. The drive measurements in Figure 3-17 were on two different anode panels and show slightly different peak stress; it is not known whether such differences arise from anode/cathode misalignment, thermal distortion of the panel assembly, or some combination of the two.…”

Section: Backward-forward Analysis Techniquementioning

confidence: 99%

Experimental and computational study of the liquid-solid transition in tin.

Foiles¹,

Davis²

2005

View full text Add to dashboard Cite

An experimental technique was developed to perform isentropic compression of heated liquid tin samples at the Z Accelerator, and multiple such experiments were performed to investigate solidification under rapid compression. Preliminary analyses, using two different methods, of data from experiments with high uncertainty in sample thickness suggest that solidification can begin to occur during isentropic compression on time scales of less than 100 ns. Repeatability of this result has not been confirmed due to technical issues on the subsequent experiments performed. First-principles molecular-dynamics calculations based on density-functional theory showed good agreement with experimentally-determined structure factors for liquid tin, and were used to investigate the equation of state and develop a novel interatomic pseudo-potential for liquid tin and its high-pressure solid phase. Empirical-potential molecular-dynamics calculations, using the new potential, gave results for the solid-liquid interface velocity, which was found to vary linearly with difference in free energy between the solid and liquid phases, as well as the liquidus, the maximum over-pressurization, and the solid-liquid interfacial energy. These data will prove useful in future modeling of solidification kinetics for liquid tin. Stephen Foiles would like to acknowledge many useful discussions with J. J. Hoyt (Org. 1814) concerning the simulation of solid-liquid interfaces. Aidan Thompson (Org. 1435) incorporated the new interatomic potential into the parallel molecular dynamics code, GRASP. Finally, Marcus Martin (Org. 1435) provided important advice on the use of the DAKOTA software package for the determination of interatomic potentials.

show abstract

Elastic constants of synthetic single crystal corundum

Abstract: The e lastic cons tan ts of sy nlh e li c sin gle c rys lal co rundum (a luminum ox id e) we re ca lc ulated from o to 900 oK from data ob lai ned by a resu nancc lec hniqu e from 80 to 900 oK.

Cited by 100 publications

References 6 publications

In-plane uniaxial magnetic anisotropy induced by anisotropic strain relaxation in high lattice-mismatched Dy/Sc superlattices

In-plane uniaxial magnetic anisotropy induced by anisotropic strain relaxation in high lattice-mismatched Dy/Sc superlattices

Reflectance spectroscopy on GaN films under uniaxial stress

Experimental and computational study of the liquid-solid transition in tin.

Contact Info

Product

Resources

About