Theory-Guided Exploration of the Sr2Nb2O7 System for Increased Dielectric and Piezoelectric Properties and Synthesis of Vanadium-Alloyed Sr2Nb2O7

Ling, Handong; Acharya, Megha; Martin, Lane W.; Persson, Kristin A.

doi:10.1021/acs.chemmater.2c00755

Cited by 3 publications

(1 citation statement)

References 34 publications

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“…Several materials have been proposed as alternatives to silica, including AlPO 4 –BPO 4 –SiO 2 ternaries, cordierite, − and several borates. − The characteristics of these compounds suggest that compounds with low atomic number atoms and open frameworks should be prioritized. Furthermore, the search for low-κ materials should be contrasted with efforts to find inorganic high-dielectric constant materials and ferroic materials − where traditionally second-order Jahn–Teller ions such as Ti 4+ and lone-pair ions such as Bi 3+ are used . These works actually aid in the search for low-κ materials by suggesting which ions should be best avoided.…”

Section: Introductionmentioning

confidence: 99%

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Morgan,

Zohar,

Lipkin

et al. 2024

Chem. Mater.

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Advances in telecommunications require electronics that operate at ever-increasing frequencies, exemplified by 5G or fifthgeneration technologies that operate in the GHz regime. At high frequencies, electrical circuits are plagued by so-called RC delays, arising from the time constant τ = RC for electrical signals which is the product of the resistance R and the capacitance C, respectively, of conductors and their insulating substrates. Besides using high quality, low-R electrical conductors such as high-purity Cu with low surface roughness, small RC delays are achieved by lowering the dielectric constant κ of the materials used in printed circuit board substrates. These largely comprise particles of an inorganic material, notably functionalized SiO 2 , embedded in a polymer-based matrix. The value of κ of the composite is primarily dictated by κ of the inorganic material. The properties of the inorganic component also impact other relevant parameters such as the quality factor, mechanical strength, and thermal expansion of the substrate. Here, we ask whether there are inorganic compounds with dielectric constants (measured at 10 GHz) that are lower than that of SiO 2 and potentially replace it in electronics. We describe the key characteristics for low-κ materials and develop a framework for screening such compounds by employing some guiding principles, followed by using a combination of empirical estimates and density functional perturbation theory-based calculations. We then report experimental results on two promising aluminum-based low-κ compounds for high-frequency applications. The first is the cristobalite form of AlPO 4 . The second is the simplest 3D metal−organic framework, aluminum formate Al(HCOO) 3 . The measured values of κ at 10 GHz, which are 4.0 for AlPO 4 and 3.8 for Al(HCOO) 3 , compare well with what is measured on SiO 2 particles.

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Section: Introductionmentioning

confidence: 99%

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Morgan,

Zohar,

Lipkin

et al. 2024

Chem. Mater.

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Growth and Inelastic Light Scattering Studies on Sr₂Nb₂O₇ Single Crystal

Suganya,

Vijayakumar,

Sivasubramanian

et al. 2024

Cryst. Res. Technol.

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A crack‐free and high structural quality Sr2Nb2O7 single crystals are grown by the optical float zone method using optimized growth parameters. The Laue pattern confirms the single crystalline nature of the grown crystal. Temperature‐dependent Raman and Brillouin light scattering studies reveal a significant shift in phonon modes across normal to incommensurate phase transition (Tn‐in) which occurs ≈488 K. In the temperature range from 900 down to 500 K, two optical phonon modes ≈63 (B1 mode) and 54 cm−1 (A1 mode) are observed. The frequency of A1 mode strongly decreases with an increase in temperature above the Tn‐in while the frequency of this mode almost remains constant below the Tn‐in. In contrast, the frequency of B1 phonon mode is found to increase with temperature in the range of 500–900 K but it does not display a significant shift below the phase transition temperature. In addition, in the in‐commensurate phase (T< 488 K), a new optical phonon mode (M1) at ≈35 cm−1 also begins to appear and exhibits strong stiffening behavior with an increase in temperature in the range of 300–488 K. Moreover, the anomalous behavior of the acoustic phonon across Tn‐in are further probed using Brilliouin scattering. Longitudinal acoustic phonon mode at 41 GHz exhibits a strong change in slope near Tn‐in. In addition, the transverse acoustic modes at 28.6 and 22.4 GHz also exhibit strong anomalies with minimum frequency near Tn‐in. The inelastic light scattering studies provide valuable information on the phase transition.

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Candidate ferroelectrics via ab initio high-throughput screening of polar materials

Ricci,

Reyes-Lillo,

Mack

et al. 2024

npj Comput Mater

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Ferroelectrics are a class of polar and switchable functional materials with diverse applications, from microelectronics to energy conversion. Computational searches for new ferroelectric materials have been constrained by accurate prediction of the polarization and switchability with electric field, properties that, in principle, require a comparison with a nonpolar phase whose atomic-scale unit cell is continuously deformable from the polar ground state. For most polar materials, such a higher-symmetry nonpolar phase does not exist or is unknown. Here, we introduce a general high-throughput workflow that screens polar materials as potential ferroelectrics. We demonstrate our workflow on 1978 polar structures in the Materials Project database, for which we automatically generate a nonpolar reference structure using pseudosymmetries, and then compute the polarization difference and energy barrier between polar and nonpolar phases, comparing the predicted values to known ferroelectrics. Focusing on a subset of 182 potential ferroelectrics, we implement a systematic ranking strategy that prioritizes candidates with large polarization and small polar-nonpolar energy differences. To assess stability and synthesizability, we combine information including the computed formation energy above the convex hull, the Inorganic Crystal Structure Database id number, a previously reported machine learning-based synthesizability score, and ab initio phonon band structures. To distinguish between previously reported ferroelectrics, materials known for alternative applications, and lesser-known materials, we combine this ranking with a survey of the existing literature on these candidates through Google Scholar and Scopus databases, revealing ~130 promising materials uninvestigated as ferroelectric. Our workflow and large-scale high-throughput screening lays the groundwork for the discovery of novel ferroelectrics, revealing numerous candidates materials for future experimental and theoretical endeavors.

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Theory-Guided Exploration of the Sr₂Nb₂O₇ System for Increased Dielectric and Piezoelectric Properties and Synthesis of Vanadium-Alloyed Sr₂Nb₂O₇

Cited by 3 publications

References 34 publications

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Growth and Inelastic Light Scattering Studies on Sr₂Nb₂O₇ Single Crystal

Candidate ferroelectrics via ab initio high-throughput screening of polar materials

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Theory-Guided Exploration of the Sr2Nb2O7 System for Increased Dielectric and Piezoelectric Properties and Synthesis of Vanadium-Alloyed Sr2Nb2O7

Cited by 3 publications

References 34 publications

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Screening Aluminum-Based Compounds as Low-κ Dielectrics for High-Frequency Applications

Growth and Inelastic Light Scattering Studies on Sr2Nb2O7 Single Crystal

Candidate ferroelectrics via ab initio high-throughput screening of polar materials

Contact Info

Product

Resources

About

Theory-Guided Exploration of the Sr₂Nb₂O₇ System for Increased Dielectric and Piezoelectric Properties and Synthesis of Vanadium-Alloyed Sr₂Nb₂O₇

Growth and Inelastic Light Scattering Studies on Sr₂Nb₂O₇ Single Crystal