Article
Acoustics
Seongmin Park, Wonju Jeon
Summary: Researchers proposed a tapered phononic beam with a unit cell consisting of two identical uniform parts and a thickness- and width-varying part. By controlling the geometrical parameters, the phononic beam achieved an ultra-broad and ultra-low frequency band gap from 3.6 Hz to 237.9 Hz.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Engineering, Mechanical
Soo-Ho Jo, Heonjun Yoon, Yong Chang Shin, Byeng D. Youn
Summary: Phononic crystals have the ability to manipulate elastic waves, with this study proposing an analytical model to reveal the fundamental mechanisms behind defect-mode-enabled energy localization. The study demonstrates that defect-mode shapes are normal modes, and that evanescent waves in a band gap play a crucial role in the formation and splitting of defect bands.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Crystallography
Soo-Ho Jo
Summary: This study examines the energy-localization performance of a one-dimensional phononic crystal with a defect under burst waves of different cycle numbers. The results show that energy-localization highly depends on the number of cycles, with better performance observed with larger cycles or continuous waves. Burst waves with a small number of cycles show limited improvement and do not induce clear energy-localized behaviors. The formation of defect-mode-enabled energy localization requires burst waves with a large number of cycles (over 500 in the case study).
Article
Acoustics
Xiao-Shuang Li, Xiao-Lei Tang, Xiao-Xing Su, Chuanzeng Zhang, Yue-Sheng Wang
Summary: In this study, three-dimensional phononic crystal-based coupled resonator waveguides (PnCCRWs) are proposed for guiding acoustic waves along complex routes. The interaction between the PnC point defects is described by the tight-binding model, enabling the propagation of acoustic wave energy along designated paths.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Xiaohua Liu, Ning Chen, Junrui Jiao, Jian Liu
Summary: This paper presents a computationally designed pneumatic soft phononic crystal for tunable band gap. By mechanically generating deformation through air pressure, the band gap in the crystal can be opened or closed, and its width can be adjusted. The study shows that pneumatic manipulation is a low-cost, fast, and easily integrated means compared to traditional mechanical deformation methods.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Physics, Applied
J. R. Li, J. C. Guo, Z. Zhang
Summary: A study on hybrid stepped phononic crystals (PnCs) finds that the reduction of periodicity in PnCs generally leads to a decrease in band gap (BG) width, but in certain cases the BG width can be increased. Understanding how the periodicity of PnCs affects the final BG characteristics is crucial for designing PnCs with high structural performance. The use of imperfect supercells with rotated unit cells demonstrates the relationship between the unit cell and the supercell, which is further utilized for wave attenuation in the proposed hybrid stepped PnCs.
MODERN PHYSICS LETTERS B
(2022)
Article
Nanoscience & Nanotechnology
Soo-Ho Jo, Heonjun Yoon, Yong Chang Shin, Wonjae Choi, Byeng D. Youn, Miso Kim
Summary: This study proposes an L-shaped arrangement of triple defects in a phononic crystal for broadband piezoelectric energy harvesting. The design effectively confines and harvests elastic-wave energy over a wide range of frequencies, overcoming the limitations of single and double defect designs.
Article
Materials Science, Multidisciplinary
Zuguang Bian, Xiaoliang Zhou
Summary: This paper introduces a discrete tuning method by transforming the phases of components, allowing for easy control of band gaps in phononic crystals in finite states. Simulations using the finite element method show significant changes in band gaps when phase transformations of components occur. This work lays the theoretical foundation for manufacturing a phononic crystal acting as an acoustic switch.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2021)
Article
Crystallography
Soo-Ho Jo, Byeng D. Youn
Summary: This study introduces a novel design concept for phononic crystals, examining differently configured double defects to achieve broadband elastic wave energy localization and harvesting.
Article
Engineering, Mechanical
Xiaopeng Zhang, Yan Li, Yaguang Wang, Zhiyuan Jia, Yangjun Luo
Summary: The study introduces a topology optimization methodology for designing narrow passband filters, which can achieve narrow defect bands at specified frequencies. Using this method, various narrow passband filtering supercell configurations with different frequencies can be achieved.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Physics, Applied
Tian-Xue Ma, Yan-Feng Wang, Xiao-Shuang Li, Chuanzeng Zhang, Yue-Sheng Wang
Summary: This paper investigates the viscoelastic effect on the topologically protected interface states in two-dimensional solid phononic crystals (PnCs). It demonstrates that even with the introduction of material viscoelasticity, the topological interface states still exist but become complex wave modes that attenuate as they propagate in the viscoelastic PnCs. The findings also show the robustness of these interface states against sharp bends or local disorders in the viscoelastic PnC structures.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Crystallography
Mohd Syafiq Faiz, Norazreen Abd Aziz
Summary: In this study, a mono-channel waveguide with alternate hollow pillars of different radius was numerically simulated using the Finite Element Method (FEM). The propagation behavior of elastic waves on the waveguide structure was studied by computing the dispersion relation, transmission coefficient, and stress displacement profile of the waveguides. The results showed that the proposed model can achieve tailorable frequency shift within the bandgap region by optimizing the inner radius of hollow pillar.
Article
Physics, Multidisciplinary
Wei Ding, Tianning Chen, Chen Chen, Dimitrios Chronopoulos, Badreddine Assouar, Yongzheng Wen, Jian Zhu
Summary: This study introduces an analogy with Thomson scattering in electromagnetic waves to characterize the bandgap phenomena in chiral phononic crystals (PnCs) with translation-rotation coupling. The coupling motion in chiral unit cells is found to be similar to the result of Thomson scattering, resulting in the formation of bandgaps.
NEW JOURNAL OF PHYSICS
(2023)
Article
Mathematics, Applied
Shunzu Zhang, Qianqian Hu, Wenjuan Zhao
Summary: This paper presents a theoretical model for the size-dependent band structure of magneto-elastic phononic crystal nanoplates. The study considers the surface effect and magneto-elastic coupling, and investigates the dependence of the band structure on various parameters. The results show that the surface effect and material intrinsic length significantly affect the band structure, and the competition between the magnetic field and pre-stress leads to nonlinear coupling characteristics. This study is important for flexible tunability of elastic wave propagation and functional design of high-performance nanoplate-based devices.
APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION
(2022)
Article
Engineering, Mechanical
Pawel Kudela, Abdalraheem Ijjeh, Maciej Radzienski, Marco Miniaci, Nicola Pugno, Wieslaw Ostachowicz
Summary: In this work, a novel approach for the topology optimization of phononic crystals using deep learning is proposed. The trained deep learning model is able to predict dispersion diagrams quickly, making it suitable for efficient optimization. The use of non-uniform rational basis spline curves and a genetic algorithm further enhances the optimization process. The method has been validated in the design of phononic crystals with cavities and offers potential for computer-assisted design of periodic structures.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Physics, Condensed Matter
A. Jbeli, N. Zeiri, N. Yahyaoui, P. Baser, M. Said
Summary: The electronic and optical properties of CdSe/ZnSe semiconductor core/shell quantum dots with hydrogenic donor impurity were investigated theoretically. The perturbation and variational methods were used to calculate the binding energy, photoionization cross-section, polarizability, and diamagnetic susceptibility of the excited impurity under various conditions. A significant stark shift in the binding energy was observed under the influence of an external electric field.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Rahat Batool, Tariq Mahmood, Sajid Mahmood, Abdul Aziz Bhatti
Summary: This study investigates the effects of alkali metal doping (Na, K, Cs) on MAPbI3 through compositional engineering. The results show that doping Na, K, and Cs can improve the phase stability, thermodynamic stability, and optical absorption of MAPbI3.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
N. A. N. M. Nor, M. A. H. Razali, W. H. A. W. K. Annuar, N. N. Alam, F. N. Sazman, N. H. M. Zaki, A. S. Kamisan, A. I. Kamisan, M. H. Samat, A. M. M. Ali, O. H. Hassan, B. U. Haq, M. Z. A. Yahya, M. F. M. Taib
Summary: This study investigates the potential of quaternary chalcogenides semiconductors as thin film solar cell absorbers using density functional theory (DFT) and density functional theory plus Hubbard U (DFT + U) approach. The results show that by applying Hubbard U terms, the electronic band gaps can be accurately predicted, providing valuable insights for finding cost-effective new thin film solar cell materials.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Ashwani Kumar, Anuj Kumar, Mohaseen S. Tamboli, Mohd Ubaidullah, J. Jayarubi, S. K. Tripathi
Summary: In this study, lead-based perovskite solar cells are replaced by bismuth-based perovskite cells to overcome their instability and toxicity. CsBi3I10 perovskite films are fabricated using a modified drop-casting process, and the effects of post-annealing temperature on the morphological, structural, and optical properties are investigated. The photovoltaic performance of the cells without a hole transport layer is also quantitatively evaluated.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yang Gao, Shu-Ming Chen, Shuo Cao, Shang-Zhou Zhang, Philippe Djemia, Qing-Miao Hu
Summary: This study investigates the phase stability, elastic modulus, and hardness of ternary nitride Ti1-xAlxN. It is found that the hardness increases with the Al content x. The cubic B1 structure is more stable for x < about 0.75, while the hexagonal structure (B4) is more stable for x > about 0.75. The composition dependent hardness and phase decomposition contribute to the convex shaped hardness curve of Ti1-xAlxN.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Fengqi Wang, Qinyan Ye, Xulin He, Kun Luo, Xiaolong Ran, Xingping Zheng, Cheng Liao, Ru Li
Summary: This report uses rigorous calculations based on density functional theory to study the piezoelectric and elastic properties of wurtzite aluminum nitride (w-AlN) with single- and co-alloying by Hf (or Zr) and Sc. The research finds that the (HfSc)0.375Al0.625N and (ZrSc)0.375Al0.625N with stable wurtzite phase have a large piezoelectric coefficient d33 of 49.18 pC/N and 47.00 pC/N, respectively. However, the piezoelectric voltage constant g33 and electromechanical coupling constant k233 of HfAlN, ZrAlN, HfScAlN, and ZrScAlN are smaller than that of ScAlN, which is attributed to the large dielectric constant epsilon 33 of Hf (or Zr) alloying samples. Furthermore, the calculations of internal parameter u and bond angle alpha elucidate the brittle-to-ductile transformation in alloying w-AlN crystal structure. Electronic structure calculations show that the bandgap decreases almost linearly with the increase of alloying concentration, and the Hf (or Zr) alloying compounds become n-type semiconductors due to the existing high-charge states.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
S. R. Athul, K. Arun, S. Swathi, U. D. Remya, Andrea Dzubinska, Marian Reiffers, Nagalakshmi Ramamoorthi
Summary: The magnetic and magnetocaloric characteristics of Ho6FeSb2 have been studied. The compound exhibits two second-order ferromagnetic transitions, enabling hysteresis-free magnetocaloric effect across a wide temperature range. The alloy has high relative cooling power and magnetoresistance, making it suitable for hysteresis-free magnetocaloric applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Reena Sharma, Neelam Hooda, Ashima Hooda, Satish Khasa
Summary: A polycrystalline double perovskite La2CoMnO6 sample was prepared and its structural, dielectric and magnetic properties were investigated. The sample exhibited complex structures and magnetic behavior, and showed good conductivity and dielectric performance. Its multi-domain magnetic structure suggests its suitability for memory device applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Shubha Dubey, Jisha A. Abraham, Kumud Dubey, Vineet Sahu, Anchit Modi, G. Pagare, N. K. Gaur
Summary: This study investigates the optoelectronic, thermodynamic, thermoelectric, and mechanical stability properties of RhTiP Half Heusler semiconductors. The results show that RhTiP is a non-magnetic material with confirmed mechanical stability. It is found to be an indirect-bandgap semiconductor with a good Seebeck coefficient. This study suggests that RhTiP has promising applications in the thermoelectric and optoelectronic fields.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Xun Xie, Jiong-Ju Hao, Hong-Wei Yang
Summary: This work presents a multilayer film structure that uses optical resonance to prepare highly efficient and saturated red, green, and blue transmittance colors. Numerical simulations and analysis show that the structure can produce R, G, and B colors with a purity comparable to standard RGB colors, while maintaining efficient transmission efficiency and obtaining a rich variety of structural colors. Additionally, a metallic interlayer is introduced to selectively suppress resonances in the short-wavelength region, improving the purity of the red color. The study also investigates the effect of the incidence angle on color purity and transmission efficiency.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yueqiang Zhao
Summary: Solubility property is of great interest in chemical, physical, pharmaceutical, material, and environmental sciences. Understanding the intrinsic reason behind solubility behavior is a fascinating task. The theoretical relation between binary mutual solubility and liquid-liquid interfacial tension has been derived, where the partitioning of solute molecules between two coexisting liquid phases is determined by the transfer free energy per unit segment for a chain-like solute molecule expressed in terms of solute-solvent interfacial tension. This general theory of solubility is in good agreement with experimental results for binary mutual solubility and molar transfer free energy of solute molecules.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Osama K. M. Bashiar, R. E. Kroon, H. C. Swart, R. A. Harris
Summary: ZnO thin films with near-infrared emission were successfully fabricated using pulsed laser deposition under vacuum conditions, without the need for additional gases or implantation methods. The NIR emission was hypothesized to be caused by defects in the ZnO film due to high energy particle impacts on the sample surface.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
O. Stognei, A. Berezutskii, I. Anisimov, A. Deryabin
Summary: The influence of ZrOn matrix stoichiometry on the electrical and magnetoresistive properties of Fe-Zr-O nanocomposites has been studied. It was found that the magnetoresistive effect is not observed in composites with oxygen lack, while composites with oxygen excess show magnetoresistive effect and increased resistivity. Magnetoresistivity in composites with oxygen lack only appears after heat treatment. These results can be explained by the difference in the density of localized states in the oxide matrix of the composites and the ratio between two types of conductivity.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Mehmet Bayirli, Aykut Ilgaz, Orhan Zeybek
Summary: The present study aims to understand the relationship between impedance characteristics and fractal behaviors. By producing neat and carbon nanotube doped composite specimens, the researchers investigated the electrical properties and surface heteromorphology using Nyquist plots and fractal analysis.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
M. I. Khan, Saddam Hussain, Muhamad Saleem, Fatimah Mohammed Alzahrani, Muhammad Siddique, M. S. Hassan, Allah Ditta Khalid, Munawar Iqbal
Summary: The sol-gel method was used to deposit Ti-doped MAPbBr3 films on FTO-glass substrates with different doping ratios (0%, 4%, and 6%). XRD analysis confirmed the cubic structure of all films, and the 4% Ti-doped film exhibited a large grain size, low band gap energy, and high refractive index. Solar cells fabricated using the 4% Ti-doped MAPbBr3 film showed improved performance in terms of current density, open circuit voltage, fill factor, and efficiency.
PHYSICA B-CONDENSED MATTER
(2024)