Article
Physics, Multidisciplinary
Oswaldo Adapta, J. Adrian Reyes
Summary: This research investigates a planar waveguide made of a cholesteric liquid crystalline elastomer with a perpendicular helical axis to the planar boundaries. The electrodynamics equations and constitutive equations are established. The mechanical stress is adjusted through elastic deformations in order to control the propagation parameters. The resulting equation system is numerically solved assuming the guide to be surrounded by air or vacuum. The band structure of the electromagnetic modes and the mixing of transverse electric and magnetic modes within the waveguide are studied.
Article
Materials Science, Ceramics
Muhamad Syaizwadi Shaifudin, Wan Mohamad Ikhmal Wan Mohamad Kamaruzzaman, Malia Athirah Badruddin, Abdul Muiz Aniq Aiman Mohd Suhaimi, Nursabrina Amirah Mohd Nasir, Nur Aiman Syafiq Mohd Hamidi, Wan Rafizah Wan Abdullah, Oon Jew Lee, Mohd Sabri Mohd Ghazali
Summary: The study analyzed the global research trend of varistors, revealing a continuous increase in publication output since 1975, with China, the United States, South Korea, and Japan being the major contributing countries. Additionally, three of the most prolific institutions associated with the research topic performed well in global university rankings.
JOURNAL OF ASIAN CERAMIC SOCIETIES
(2022)
Article
Materials Science, Multidisciplinary
Yumeng Zheng, Yuuki Sato, Shinzo Yoshikado
Summary: The optimal amount of B2O3 significantly improved the electrical properties of Y-doped varistors, reducing leakage current and maintaining long-term stability. Excessive B2O3 content led to changes in microstructure, affecting donor density and barrier structure, consequently altering electrical properties.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Fuad Alhaj Omar
Summary: The study analyzed the impact of structural inhomogeneity on the electrical properties of zinc oxide-based varistors and manufactured a new varistor with reasonable structural homogeneity and good nonlinear characteristics for absorbing excess voltage. The new varistor demonstrated the ability to withstand regular high pulses without puncture failure, indicating its effectiveness in absorbing excess voltage.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Physics, Multidisciplinary
Fatemeh Ahmadzadeh, Ali Bahrami
Summary: A two-dimensional gradient-index phononic crystal composed of aluminum scatterers in an air matrix has been designed and simulated. The path of waves inside the structure is shown using analytical solutions. By increasing the filling factor, the structure can be mechanically tuned, resulting in a shift in the focal point while maintaining a nearly constant spot size.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Shintaro Fujii, Enrique Montes, Haruna Cho, Yi Yue, Masaaki Koike, Tomoaki Nishino, Hector Vazquez, Manabu Kiguchi
Summary: In this paper, the tuning of the thermopower of single-molecule junctions of fullerene, 4,4'-bipyridine, and p-phenylenediamine using scanning tunneling microscopy-based break junction technique is demonstrated. The thermoelectric voltage of the junction is tuned by mechanically controlling the tip-electrode separation distance. The atomistic simulations illustrate the shifts in the conduction orbital energies induced by the mechanical compression of the junctions.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Sk Mehebub Rahaman, Madhuparna Chakraborty, Trishna Mandal, Sandip Kundu, Subhendu Dhibar, Dileep Kumar, Samia M. Ibrahim, Manab Chakravarty, Bidyut Saha
Summary: This study investigates the growth process of lanthanum carbonate nanorods in W/O microemulsions. The initial nucleation dominant growth period forms spherical droplets, which then deviate from spherical shape and evolve into nanorods. The presence of a double bond in the surfactant molecules is responsible for the anisotropic growth. The low water content in the microemulsion inhibits the growth rate of the nanoparticles.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Electrical & Electronic
Zhijun Xu, Yanliang Wei, Shuai Ma, Xianjun Guo, Guorong Li, Ruiqing Chu, Jianxun Qiu
Summary: Low breakdown electric field ZnO-Bi2O3-TiO2-Co2O3-MnO2 (ZBTCM) varistor ceramics doped with various amounts of B2O3 were prepared by the solid-state reactions. The sintering temperature was 900 degrees C, lower than the melting point of pure silver. The microstructural features and electrical properties were investigated by XRD, SEM and a capacitance meter. The results show that B2O3 is not only a sintering additive, but also an electrical property improver. ZBTCM based varistors with breakdown field of 131.25 V/mm, nonlinear coefficient (alpha) of 39.13 and leakage current density (J(L)) lower than 2.5 mu A/mm(2) were obtained by doping 1 wt% B2O3 sintered at 900 degrees C.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Chemistry, Physical
Guoxu Liu, Ruifei Luan, Youchao Qi, Likun Gong, Jie Cao, Zhihao Wang, Feng Liu, Jianhua Zeng, Xinlong Huang, Yuhan Qin, Sicheng Dong, Yuan Feng, Long-Biao Huang, Chi Zhang
Summary: This research presents a direct current flexible textile organic tribovoltaic nanogenerator (FT-OTG) that improves the output performance and mechanical properties of FT-OTG. The FT-OTG is composed of a blended film of PEDOT: PSS and PVA, a conductive ink, a conductive textile, and an Al slider. The improved FT-OTG can be used for self-powered portable electronic devices and Internet of Things (IoT) sensors.
Article
Chemistry, Physical
Navdeep Singh Grewal, Gaurav Kumar Sharma, Kamal Kumar, Uma Batra
Summary: The advent of magnesium (Mg) alloys has brought about a paradigm shift in the field of biomedical implants due to their biodegradability, mechanical strength, and biocompatibility. However, the rapid degradation of Mg alloys in physiological conditions compromises their integrity and biocompatibility, hindering their clinical translation.
SURFACES AND INTERFACES
(2023)
Article
Engineering, Biomedical
Yu Jung Shin, Ryan T. Shafranek, Jonathan H. Tsui, Jelisha Walcott, Alshakim Nelson, Deok-Ho Kim
Summary: 3D bioprinting is a powerful technique for engineering tissues, providing native biological and mechanical cues. By using bio-based materials, bioinks with cellular adhesion, differentiation, and proliferation abilities can be successfully prepared.
ACTA BIOMATERIALIA
(2021)
Article
Materials Science, Ceramics
Lucia Fernandez Garcia, Feridoon Azough, Gareth Parsons, Amanda Quadling, Bing Wang, Robert Freer
Summary: The study found that SiC varistor performance is significantly influenced by SiC grain size, composition, and graphite content. Higher graphite content leads to lower non-linear coefficient and breakdown field. Decreasing SiC grain size results in increased non-linear coefficient and breakdown field strength.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Mathematics, Applied
Yilin Qu, Feng Jin, Jiashi Yang
Summary: This study investigates the electromechanical fields in a sandwich plate with a flexoelectric semiconductor layer between two piezomagnetic dielectric layers under a transverse magnetic field. Two-dimensional equations for the plate bending are derived from the macroscopic theory of piezomagnetics and flexoelectric semiconductors. Several solutions are obtained for static and time-harmonic magnetic loadings. Different magnetic fields can generate various distributions of mobile charges and electric fields, which is fundamental in flexotronics. In the case of pure bending under a uniform magnetic field, a coefficient is identified to characterize the strength of the interaction between the applied magnetic field and the mobile charges, which reaches its maximum at a specific thickness ratio between the two types of material layers. The frequency dependence of the coupling coefficient in time-harmonic motions is also determined.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Energy & Fuels
Xiaolei Zhao, Jun Hu, Xiao Yang, Zhiwen Huang, Xingming Bian, Yuanbao Lin, Jinliang He
Summary: The effects of different particle sizes of hybrid zinc oxide micro-spherical varistors on the electrical, mechanical, and thermal properties were investigated. It was found that increasing the size of the varistors in the composites can lower the switching field but degrade the mechanical properties and stability of the nonlinear conductivity. However, incorporating a mixture of hybrid varistors with different sizes into silicone rubber resulted in composites with low switching field, stable nonlinear conductivity, and excellent mechanical and thermal properties. These findings are valuable for controlling the performance of advanced field-grading materials and enhancing the stability and durability of electronic and electrical devices.
CSEE JOURNAL OF POWER AND ENERGY SYSTEMS
(2023)
Article
Chemistry, Multidisciplinary
Xinhai Zhang, Kai Liu, Jun Zhao, Zhaoming Zhang, Zhen Luo, Yuchen Guo, Hao Zhang, Yongming Wang, Ruixue Bai, Dong Zhao, Xue Yang, Yuhang Liu, Xuzhou Yan
Summary: The concept of mechanically interlocked aerogels (MIAs) is proposed in this study, which integrates mechanical adaptivity and multifunctionality in a single entity. The MIAs possess a good appearance and hierarchical pores. The MIAs demonstrate mechanical robustness, adaptivity, and responsiveness, and also show favorable performance in iodine uptake, thermal insulation, and selective adsorption of organic dyes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Ceramics
Stephan Stich, Kuan Ding, Qaisar Khushi Muhammad, Lukas Porz, Christian Minnert, Wolfgang Rheinheimer, Karsten Durst, Juergen Roedel, Till Froemling, Xufei Fang
Summary: Experimental modulation of dislocation-based plasticity in single-crystal SrTiO3 by increasing oxygen vacancy concentration impacts dislocation nucleation and motion. This is evidenced by nanoindentation and bulk compression tests on a nano-/microscale level.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Lalitha Kodumudi Venkataraman, Till Froemling, Juergen Roedel
Summary: Na1/2Bi1/2TiO3-based materials have potential for high-power ultrasonic applications. The inclusion of ZnO stabilizes the ferroelectric equilibrium and improves the thermal depolarization temperature and mechanical quality factor. The influence of the matrix NBTyBT phase is investigated, revealing different performances of composites with different phases.
JOURNAL OF MATERIOMICS
(2022)
Article
Chemistry, Physical
Fan Yang, Yidong Hu, Qiaodan Hu, Sebastian Steiner, Till Froemling, Linhao Li, Patrick Wu, Emilio Pradal-Velazquez, Derek C. Sinclair
Summary: The research found that the polymorphic form of TiO2 reagent has a significant impact on the electrical conductivity and conduction mechanism of NBT ceramics. NBT prepared with rutile TiO2 is ionically conductive, while NBT prepared with anatase TiO2 is insulating. This highlights the importance of selecting the appropriate TiO2 reagent for different applications of NBT-based ceramics.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
Leonie Koch, Sebastian Steiner, An-Phuc Hoang, Arne J. Klomp, Karsten Albe, Till Froemling
Summary: Solid solutions of sodium bismuth titanate (NBT) are the most performant lead-free dielectric ceramics for energy storage. The defect chemistry of NBT is complex, and acceptor doping can result in unexpected and extraordinarily high oxygen ionic conductivity. This study elucidates the interaction between acceptors and oxygen vacancies and rationalizes the observed differences in conductivity through experiments and calculations.
Article
Materials Science, Ceramics
Ju-Hyeon Lee, Geon-Ju Lee, An-Phuc Hoang, Till Froemling, Thuy-Linh Pham, Jong-Sook Lee, Wook Jo
Summary: Dielectrics for automobile applications require high temperature reliability. Bi(1/2)Nau(1/2)TiO(3)-based materials are excellent candidates with large temperature-insensitive dielectric responses and a maximum dielectric permittivity temperature of up to 300 degrees C. However, their high dielectric loss increases exponentially above 200 degrees C due to ionic conduction. This study demonstrates that introducing a sodium deficiency and thermal annealing can effectively suppress the impact of ionic conduction on dielectric loss, elevating the temperature insensitivity of the dielectric loss up to approximately 300 degrees C.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Maximilian Kissel, Lukas Porz, Till Froemling, Atsutomo Nakamura, Juergen Roedel, Marin Alexe
Summary: This study reveals that dislocations in oxide semiconductors can enhance the photoconductivity and result in different global photoconductivity behavior. Additionally, indications for a bulk photovoltaic effect enabled by dislocation-surrounding strain fields are observed for the first time.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Ceramics
Amir Sohail Khan, Burhan Ullah, Nikola Novak, Hamayun Khan, Amir Ullah
Summary: The structural instability, relaxor ferroelectricity, and microwave dielectric properties of Sr(1-x)CexTi(1-2/3y)MgyO3 ceramic samples (sintered in 5%H2 and 95%N2 atmosphere) were systematically studied. The results show that the structural symmetry of the samples varies with different doping concentrations, and there is a frequency-dependent dielectric maxima and intrinsic ferroelectric nature. The sample with x=0.15 exhibits low microwave dielectric permittivity, good temperature stability of resonance frequency, and high Q-factor.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Lukas Porz, Michael Scherer, Qaisar Khushi Muhammad, Kimitaka Higuchi, Yan Li, Shuhei Koga, Atsutomo Nakamura, Wolfgang Rheinheimer, Till Froemling
Summary: Blacklight sintering technology enables rapid densification of ceramics with precise process control and excellent material quality.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Nicole Bein, Brigita Kmet, Tadej Rojac, Andreja Bencan Golob, Barbara Malic, Julian Moxter, Thorsten Schneider, Lovro Fulanovic, Maryam Azadeh, Till Froemling, Sonja Egert, Hongguang Wang, Peter van Aken, Jutta Schwarzkopf, Andreas Klein
Summary: The valence band maximum energy of NaNbO3 is determined and found comparable to SrTiO3 and BaTiO3, while the conduction band minimum is yet to be determined. In addition, Sr- and Ca-doped NaNbO3 ceramics exhibit low electrical conductivity.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Qaisar Khushi Muhammad, Michael Scherer, Alexander Karl Opitz, Stefanie Taibl, Christin Boehme, Marcus Rohnke, Juergen Janek, Shuang Gao, Juergen Fleig, Till Froemling
Summary: This study investigates the influence of mechanically induced dislocations on the electrical conductivity and oxygen transport in YSZ. Distinctly aligned regions with abundant and deficient dislocations are generated using advanced mechanical deformation methods. Electrical characterization reveals highly conducting effects of dislocation-induced strain within the material. Targeted oxygen tracer diffusion experiments confirm the enrichment of oxygen incorporation within the dislocation bundles. Therefore, mechanically induced dislocations have the potential to serve as a design element for tuning bulk ionic transport in YSZ.
Article
Physics, Condensed Matter
Nikola Novak, Dejvid Cresnar, George Cordoyiannis, Rasa Pirc
Summary: A Landau phenomenological approach is used to calculate the polarization, dipolar entropy, and free energy in ferroelectric and antiferroelectric materials, revealing that the inverse electrocaloric effect is caused by the antiparallel alignment of polarization with the applied electric field, leading to a decrease in free energy density and an increase in dipolar entropy.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Materials Science, Ceramics
Qaisar Khushi Muhammad, Marcela Valderrama, Mengkun Yue, Alexander Karl Opitz, Stefanie Taibl, Matthaus Siebenhofer, Enrico Bruder, Juergen Fleig, Xufei Fang, Till Froemling
Summary: Tailoring the electrical conductivity of functional ceramics through introducing dislocations has recently been a focus of research, and its merits have been demonstrated through mechanical means. However, controlling the generation and annihilation of dislocations remains difficult. In this study, a micromechanical approach was used to demonstrate control over these aspects on yttria-stabilized zirconia (YSZ). The results showed a significant enhancement in conductivity in dislocation-rich regions compared to pristine ones, mainly attributed to oxygen ionic conductivity. This study illustrates the possibility of increasing conductivity and provides a prospect for transferring the merits of dislocation-tuned electrical conductivity to solid oxygen electrolytes.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Nikola Novak, Florian Weyland, Nasser Khakpash, George A. Rossetti Jr
Summary: The composition-temperature-electric field diagram and electrocaloric properties of BaTi1_xZrxO3 (BZT) were calculated. The adiabatic temperature change due to material polarization at critical end, tricritical, and phase convergence points was quantified. The largest temperature change occurred at the first-order paraelectric to ferroelectric transitions, while the greatest material polarization contribution was observed at the critical temperature. The maximum electrocaloric responsivity occurred at a field 1.25 times greater than the critical field. The enhanced temperature change near the convergence point was attributed to greater polarization change in the rhombohedral phase and a polar glasslike state that contributed to the dipolar configurational entropy.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Afaak Lakouader, Youness Hadouch, Daoud Mezzane, Valentin Laguta, M'barek Amjoud, Voicu O. Dolocan, Nikola Novak, Lahoucine Hajji, El Hassan Choukri, Anna Razumnaya, Abdelhadi Alimoussa, Zdravko Kutnjak, Igor A. Luk'yanchuk, Mimoun El Marssi
Summary: La0.8Sr0.2MnO3 (LSMO) nanopowders were synthesized using two different methods and their nanoparticle sizes, structural, magnetic, and magnetocaloric properties were compared. LSMO-PC exhibited larger nanoparticle sizes and superior magnetic and magnetocaloric properties, while LSMO-AC displayed significant magnetocaloric thermal stability.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Ceramics
Maximilian Gehringer, An-Phuc Hoang, Lovro Fulanovic, Kostja Makarovic, Barbara Malic, Till Fromling
Summary: Currently, research on capacitor materials for high-temperature and power electronics focuses on achieving new record-breaking limits for dielectric properties or energy storage densities, with little regard for the stability of key parameters during operation or component reliability. Multilayer ceramic capacitors based on lead-free sodium bismuth titanate with AgPd inner electrodes have exhibited exceptional stability of properties and capacitance at high temperatures and voltages during operation, which can help to open up the field of high-temperature and power electronics. Despite the lack of precise requirements and limits specified by manufacturers and industry, their extensive stability of dielectric properties allows for a rather universal application.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)