Theoretical study of AlN mechanical behaviour under high pressure regime

Zagorac, Dejan; Zagorac, Jelena; Djukic, Milos B.; Jordanov, Dragana; Matović, Branko

doi:10.1016/j.tafmec.2019.102289

Cited by 28 publications

(20 citation statements)

References 49 publications

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“…Thus, an isotropic Young's modulus is expected in contrast to the calculated moduli. However, the achieved result is in agreement with theoretical investigations of the anisotropy of wurtzite AlN [46]. Though there is no epitaxial relationship between ScAlN, Pt and silicon, the use of (111) oriented Si leads to a weak preferential orientation of the (111) oriented Pt and the subsequent hexagonal ScAlN layer.…”

Section: Resultssupporting

confidence: 87%

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Krey

Hähnlein

Tonisch

et al. 2020

Sensors

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Magnetoelectric sensors provide the ability to measure magnetic fields down to the pico tesla range and are currently the subject of intense research. Such sensors usually combine a piezoelectric and a magnetostrictive material, so that magnetically induced stresses can be measured electrically. Scandium aluminium nitride gained a lot of attraction in the last few years due to its enhanced piezoelectric properties. Its usage as resonantly driven microelectromechanical system (MEMS) in such sensors is accompanied by a manifold of influences from crystal growth leading to impacts on the electrical and mechanical parameters. Usual investigations via nanoindentation allow a fast determination of mechanical properties with the disadvantage of lacking the access to the anisotropy of specific properties. Such anisotropy effects are investigated in this work in terms of the Young’s modulus and the strain on basis of a MEMS structures through a newly developed fully automated procedure of eigenfrequency fitting based on a new non-Lorentzian fit function and subsequent analysis using an extended Euler–Bernoulli theory. The introduced procedure is able to increase the resolution of the derived parameters compared to the common nanoindentation technique and hence allows detailed investigations of the behavior of magnetoelectric sensors, especially of the magnetic field dependent Young‘s modulus of the magnetostrictive layer.

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Section: Resultssupporting

confidence: 87%

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Krey

Hähnlein

Tonisch

et al. 2020

Sensors

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“…In terms of theoretical calculations relative to those reported in [28] using all-electron full potential linearized augmented plane wave approaches, our LDA results in good consistency with the experiment [30]. For pressures varying between 0 and 40 GPa, our LDA values for a and c are compared to those of [31] and are shown to be lower. All parameters a, c, c/a and u are seen in Fig1.…”

Section: Structural Propertiessupporting

confidence: 78%

“…The elastic constant results derived by the Abinit code shown in [32]. and our LDA was found to be lower than [31] for pressure ranging from 0 to 40 GPa. The influence of hydrostatic pressure enables us to consider the mechanical stability and phase transition mechanisms of interatomic interactions.…”

Section: Elastic and Related Mechanical Propertiesmentioning

confidence: 54%

Significant improvement in the piezoelectric properties and electromechanical coupling factors of wurtzite AlN compound under high pressures

et al. 2021

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This work describes a theoretical study of the pressure effect in structural, elastic, piezoelectric and dielectric properties as well as electromechanical coupling factors of wurtzite AlN, obtained by ab-initio calculations using pseudo-potential plane waves (PP-PW) that combine the density functional theory (DFT) and density functional perturbation theory (DFPT). The results of the calculation indicate that the parameters of AlN crystal cells and the volume of AlN crystallin crystal cells decrease notably with increasing pressures from 0 to 40 GPa. Due to an increase in the value of the direct piezoelectric constant ( 33 and a decrease in the value of the elastic constant ( 33 ), there is a significant improvement in the value of the converse piezoelectric constant ( 33 ). The improvement in the piezoelectric value leads to a higher value in electromechanical coupling coefficient. Our results agree well with previous theoretical and experimental research. We hope that our results will provide guidelines for the realistic application as well as further research of high-performance compounds appropriate for applications in a multitude of fields of study, such as biomedical engineering.

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“…a pseudopotential [42] was used, together with a [4s4p2d3f] basis set, for O 2a [4s3p] basis set was used, [43,44] and for N 3-[3s2p] an all-electron basis set based on Gaussian-type orbitals was employed. [45,46] The symmetries of the analyzed structures were determined using the SFND [47] and RGS [48] algorithms implemented in the program KPLOT. [49] Structures were visualized using the Vesta software.…”

Section: Computational Detailsmentioning

confidence: 99%

Predicting Feasible Modifications of Ce2ON2 Using a Combination of Global Optimization and Data Mining

Zagorac

Schön

Matović

et al. 2020

J. Phase Equilib. Diffus.

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Using a combination of global optimization and data mining, we identify feasible modifications of an ionic Ce-O-N ceramic compound, with composition Ce 2 ON 2 , that should at least be metastable at T = 0 K. The energy landscape of Ce 2 ON 2 has been explored for various pressures using empirical potentials followed by ab initio level optimizations, and a multitude of structure candidates has been analyzed. The structure of the energetically lowest modification among these candidates at standard pressure, a-Ce 2 ON 2 , is predicted to be similar to the AlCo 2 Pr 2 structure type.

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Theoretical study of AlN mechanical behaviour under high pressure regime

Cited by 28 publications

References 49 publications

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Significant improvement in the piezoelectric properties and electromechanical coupling factors of wurtzite AlN compound under high pressures

Predicting Feasible Modifications of Ce2ON2 Using a Combination of Global Optimization and Data Mining

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