Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

11,001 Full-Text Articles 16,173 Authors 2,175,838 Downloads 124 Institutions

All Articles in Materials Science and Engineering

Faceted Search

11,001 full-text articles. Page 3 of 300.

Monoclinic Phases Arising Across Thermal Inter-Ferroelectric Phase Transitions, Yijia Gu, Fei Xue, Shiming Lei, Tom T. A. Lummen, Jianjun Wang 2019 Missouri University of Science and Technology

Monoclinic Phases Arising Across Thermal Inter-Ferroelectric Phase Transitions, Yijia Gu, Fei Xue, Shiming Lei, Tom T. A. Lummen, Jianjun Wang

Yijia Gu

Thermotropic phase boundaries (TPBs), as thermal analogs of morphotropic phase boundaries (MPBs), are associated with the thermal inter-ferroelectric phase transitions. Similar to an MPB, a TPB exhibits a characteristically flattened energy profile which favors polarization rotation, thus giving rise to a structurally bridging low-symmetry phase. We report on the kinetic process of thermal inter-ferroelectric phase transitions in BaTiO3 and KNbO3 using the phase-field method. The domain structures are found to play key roles in stabilizing the monoclinic phase. In simple domain structures, the monoclinic phase is a transient phase and cannot be stabilized into its neighboring phase regimes ...


Nanoscale Mechanical Switching Of Ferroelectric Polarization Via Flexoelectricity, Yijia Gu, Zijian Hong, Jason Britson, Long-Qing Chen 2019 Missouri University of Science and Technology

Nanoscale Mechanical Switching Of Ferroelectric Polarization Via Flexoelectricity, Yijia Gu, Zijian Hong, Jason Britson, Long-Qing Chen

Yijia Gu

Flexoelectric coefficient is a fourth-rank tensor arising from the coupling between strain gradient and electric polarization and thus exists in all crystals. It is generally ignored for macroscopic crystals due to its small magnitude. However, at the nanoscale, flexoelectric contributions may become significant and can potentially be utilized for device applications. Using the phase-field method, we study the mechanical switching of electric polarization in ferroelectric thin films by a strain gradient created via an atomic force microscope tip. Our simulation results show good agreement with existing experimental observations. We examine the competition between the piezoelectric and flexoelectric effects and provide ...


Low-Symmetry Monoclinic Ferroelectric Phase Stabilized By Oxygen Octahedra Rotations In Strained EuXSr1-XTio₃ Thin Films, Anna N. Morozovska, Yijia Gu, Victoria V. Khist, Maya D. Glinchuk, Long-Qing Chen 2019 Missouri University of Science and Technology

Low-Symmetry Monoclinic Ferroelectric Phase Stabilized By Oxygen Octahedra Rotations In Strained EuXSr1-XTio₃ Thin Films, Anna N. Morozovska, Yijia Gu, Victoria V. Khist, Maya D. Glinchuk, Long-Qing Chen

Yijia Gu

Using Landau-Ginzburg-Devonshire theory and phase-field modeling, we explore the complex interplay between a structural order parameter (oxygen octahedron rotation) and polarization in EuxSr1-xTiO3 thin films. Under a biaxially tensile strain, a low-symmetry monoclinic phase with in-plane ferroelectric polarization is found to be stabilized by antiferrodistortive oxygen octahedra tilts. The monoclinic phase is stable over a wide temperature range. It is characterized by a large number of energetically equivalent polar and structural twin domains. This work demonstrates the development of a spontaneous polarization and piezo- and pyroelectricity in a ferroelastic twin boundary arising from flexoelectric coupling ...


Erratum: "Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films" (Applied Physics Letters 106:162904 (2015)), Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He 2019 Missouri University of Science and Technology

Erratum: "Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films" (Applied Physics Letters 106:162904 (2015)), Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He

Yijia Gu

There is a typo of the space group. All the Pnmb should be Pbnm (or Pnma). So the Glazer notation should be changed to (a−a−c+) for Pbnm space group on page 4 of the article.1 We have also noticed that the thermodynamic analysis of CaTiO3 thin film is not correct.


Evolution Of The Statistical Distribution In A Topological Defect Network, Fei Xue, Xueyun Wang, Ion Socolenco, Yijia Gu, LongQing Chen, Sang-Wook Cheong 2019 Missouri University of Science and Technology

Evolution Of The Statistical Distribution In A Topological Defect Network, Fei Xue, Xueyun Wang, Ion Socolenco, Yijia Gu, Longqing Chen, Sang-Wook Cheong

Yijia Gu

The complex networks of numerous topological defects in hexagonal manganites are highly relevant to vastly different phenomena from the birth of our cosmos to superfluidity transition. The topological defects in hexagonal manganites form two types of domain networks: type-I without and type-II with electric self-poling. A combined phase-field simulations and experimental study shows that the frequencies of domains with N-sides, i.e. of N-gons, in a type-I network are fitted by a lognormal distribution, whereas those in type-II display a scale-free power-law distribution with exponent ~ 2. A preferential attachment process that N-gons with a larger N have higher probability of ...


Large Kinetic Asymmetry In The Metal-Insulator Transition Nucleated At Localized And Extended Defects, W. Fan, Jinbo Cao, J. Seidel, Yijia Gu, J. W. Yim 2019 Missouri University of Science and Technology

Large Kinetic Asymmetry In The Metal-Insulator Transition Nucleated At Localized And Extended Defects, W. Fan, Jinbo Cao, J. Seidel, Yijia Gu, J. W. Yim

Yijia Gu

Superheating and supercooling effects are characteristic kinetic processes in first-order phase transitions, and asymmetry between them is widely observed. In materials where electronic and structural degrees of freedom are coupled, a wide, asymmetric hysteresis may occur in the transition between electronic phases. Structural defects are known to seed heterogeneous nucleation of the phase transition, hence reduce the degree of superheating and supercooling. Here we show that in the metal-insulator transition of single-crystal VO 2, a large kinetic asymmetry arises from the distinct spatial extension and distribution of two basic types of crystal defects: point defects and twin walls. Nanometer-thick twin ...


First-Principles Study Of 180⁰ Domain Walls In Batio₃: Mixed Bloch-Néel-Ising Character, Menglei Li, Yijia Gu, Yi Wang, Long-Qing Chen, Wenhui Duan 2019 Missouri University of Science and Technology

First-Principles Study Of 180⁰ Domain Walls In Batio₃: Mixed Bloch-Néel-Ising Character, Menglei Li, Yijia Gu, Yi Wang, Long-Qing Chen, Wenhui Duan

Yijia Gu

The 180⁰ ferroelectric domain walls (FDWs) have long been regarded as purely Ising type in ferroelectrics, but recent theoretical works suggested that they can also have Néel- and/or Bloch-like rotations. Using a combination of first-principles calculations with phase-field simulations, we studied the 180⁰ FDWs on different crystallographic planes in prototypical ferroelectric perovskite BaTiO3. The polarization profiles of 180 FDWs on (100) and (410) planes revealed that the (100)- and (410)-FDWs both exhibit Néel-like character besides their intrinsic Ising character, while the (410)-FDW also simultaneously shows a Bloch-like oblique of ~6 nm, as a consequence of the ...


Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films, Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He 2019 Missouri University of Science and Technology

Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films, Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He

Yijia Gu

Epitaxial strain is a powerful tool to induce functional properties such as ferroelectricity in thin films of materials that do not possess ferroelectricity in bulk form. In this work, a ferroelectric state was stabilized in thin films of the incipient ferroelectric, CaTiO3, through the careful control of the biaxial strain state and TiO6 octahedral rotations. Detailed structural characterization was carried out by synchrotron x-ray diffraction and scanning transmission electron microscopy. CaTiO3 films grown on La0.18Sr0.82Al0.59Ta0.41O3 (LSAT) and NdGaO3 (NGO) substrates experienced a 1 ...


Flexoelectricity And Ferroelectric Domain Wall Structures: Phase-Field Modeling And Dft Calculations, Yijia Gu, Menglei Li, Anna N. Morozovska, Yi Wang, Eugene A. Eliseev 2019 Missouri University of Science and Technology

Flexoelectricity And Ferroelectric Domain Wall Structures: Phase-Field Modeling And Dft Calculations, Yijia Gu, Menglei Li, Anna N. Morozovska, Yi Wang, Eugene A. Eliseev

Yijia Gu

We show that flexoelectric effect is responsible for the non-Ising character of a 180° ferroelectric domain wall. The wall, long considered being of Ising type, contains both Bloch- and Néel-type polarization components. Using the example of classic ferroelectric BaTiO3, and by incorporating the flexoelectric effect into a phase-field model, it is demonstrated that the flexoelectric effect arising from stress inhomogeneity around the domain wall leads to the additional Bloch and Néel polarization components. The magnitudes of these additional components are two or three magnitudes smaller than the Ising component, and they are determined by the competing depolarization and flexoelectric fields ...


Erratum: Orientations Of Low-Energy Domain Walls In Perovskites With Oxygen Octahedral Tilts (Physical Review B - Condensed Matter And Materials Physics (2014) 90 (220101)), Fei Xue, Yijia Gu, Linyun Liang, Yi Wang, Long-Qing Chen 2019 Missouri University of Science and Technology

Erratum: Orientations Of Low-Energy Domain Walls In Perovskites With Oxygen Octahedral Tilts (Physical Review B - Condensed Matter And Materials Physics (2014) 90 (220101)), Fei Xue, Yijia Gu, Linyun Liang, Yi Wang, Long-Qing Chen

Yijia Gu

In the Acknowledgment of the original article, the Award No. DMR-0820404 should be replaced by DMR-1420620.


Erratum: "Composition- And Pressure-Induced Ferroelectric To Antiferroelectric Phase Transitions In Sm-Doped Bifeo₃ System" [Appl. Phys. Lett. 106, 012903 (2015)], Fei Xue, Linyun Liang, Yijia Gu, Ichiro Takeuchi, Sergei V. Kalinin, Long-Qing Chen 2019 Missouri University of Science and Technology

Erratum: "Composition- And Pressure-Induced Ferroelectric To Antiferroelectric Phase Transitions In Sm-Doped Bifeo₃ System" [Appl. Phys. Lett. 106, 012903 (2015)], Fei Xue, Linyun Liang, Yijia Gu, Ichiro Takeuchi, Sergei V. Kalinin, Long-Qing Chen

Yijia Gu

In the acknowledgement of the original article,1 the Award No. DMR-0820404 should be replaced by DMR-1420620.


Electric Field-Induced Tetragonal To Orthorhombic Phase Transitions In [110]C-Oriented Batio₃ Single Crystals, D. J. Franzbach, Yijia Gu, Long-Qing Chen, K. G. Webber 2019 Missouri University of Science and Technology

Electric Field-Induced Tetragonal To Orthorhombic Phase Transitions In [110]C-Oriented Batio₃ Single Crystals, D. J. Franzbach, Yijia Gu, Long-Qing Chen, K. G. Webber

Yijia Gu

Electric field-induced phase transitions in [110]c-oriented BaTiO3 single crystals were studied by macroscopic electrical measurements in the temperature range from 20 °C to 50 °C. Discontinuous, hysteretic jumps in the polarization and strain were observed, indicating a tetragonal ↔ orthorhombic phase transition. The critical electric field to induce the transition was found to shift to higher values with increasing temperature. The Landau-Devonshire theory was used to analyze the observed electric field-induced T ↔ O phase transitions.


Electric-Field Induced Ferromagnetic Phase In Paraelectric Antiferromagnets, Maya D. Glinchuk, Eugene A. Eliseev, Yijia Gu, Long-Qing Chen, Venkatraman Gopalan, Anna N. Morozovska 2019 Missouri University of Science and Technology

Electric-Field Induced Ferromagnetic Phase In Paraelectric Antiferromagnets, Maya D. Glinchuk, Eugene A. Eliseev, Yijia Gu, Long-Qing Chen, Venkatraman Gopalan, Anna N. Morozovska

Yijia Gu

The phase diagram of a quantum paraelectric antiferromagnet EuTiO33 under an external electric field is calculated using Landau-Ginzburg-Devonshire theory. The application of an electric field E in the absence of strain leads to the appearance of a ferromagnetic (FM) phase due to the magnetoelectric (ME) coupling. At an electric field greater than a critical field, Ecr, the antiferromagnetic (AFM) phase disappears for all considered temperatures, and FM becomes the only stable magnetic phase. The calculated value of the critical field is close to the values reported recently by Ryan et al. [Nat. Commun. 4, 1334 (2013)10 ...


Conductivity Of Twin-Domain-Wall/Surface Junctions In Ferroelastics: Interplay Of Deformation Potential, Octahedral Rotations, Improper Ferroelectricity, And Flexoelectric Coupling, Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Borisevich, Long-Qing Chen 2019 Missouri University of Science and Technology

Conductivity Of Twin-Domain-Wall/Surface Junctions In Ferroelastics: Interplay Of Deformation Potential, Octahedral Rotations, Improper Ferroelectricity, And Flexoelectric Coupling, Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Borisevich, Long-Qing Chen

Yijia Gu

Electronic and structural phenomena at the twin-domain-wall/surface junctions in the ferroelastic materials are analyzed. Carriers accumulation caused by the strain-induced band structure changes originated via the deformation potential mechanism, structural order parameter gradient, rotostriction, and flexoelectric coupling is explored. Approximate analytical results show that inhomogeneous elastic strains, which exist in the vicinity of the twin-domain-wall/surface junctions due to the rotostriction coupling, decrease the local band gap via the deformation potential and flexoelectric coupling mechanisms. This is the direct mechanism of the twin-wall static conductivity in ferroelastics and, by extension, in multiferroics and ferroelectrics. On the other hand, flexoelectric ...


Composition- And Pressure-Induced Ferroelectric To Antiferroelectric Phase Transitions In Sm-Doped Bifeo₃ System, Fei Xue, Linyun Liang, Yijia Gu, Ichiro Takeuchi, Sergei V. Kalinin, Long-Qing Chen 2019 Missouri University of Science and Technology

Composition- And Pressure-Induced Ferroelectric To Antiferroelectric Phase Transitions In Sm-Doped Bifeo₃ System, Fei Xue, Linyun Liang, Yijia Gu, Ichiro Takeuchi, Sergei V. Kalinin, Long-Qing Chen

Yijia Gu

A three-dimensional phenomenological model is proposed to describe both ferroelectricity and antiferroelectricity based on the Ginzburg-Landau-Devonshire theory. Its application to the multiferroic Sm-doped BiFeO3 system describes the temperature-, pressure-, and composition-induced ferroelectric to antiferroelectric phase transitions. The constructed temperature-composition and temperature-pressure phase diagrams show that compressive hydrostatic pressure and Sm doping have similar effects on the ferroelectric and antiferroelectric phase transitions. It is also indicated from the temperature-pressure phase diagram that the experimentally observed phase of BiFeO3 under the hydrostatic pressure from 3 GPa to 10 GPa is a PbZrO3-like antiferroelectric phase.


Magneto-Active Slosh Control System Using Free Floating Membrane For Cylinderical Propellant Tanks Read More: Https://Arc.Aiaa.Org/Doi/Abs/10.2514/6.2019-2177, Pedro Llanos 2019 Embry-Riddle Aeronautical University - Daytona Beach

Magneto-Active Slosh Control System Using Free Floating Membrane For Cylinderical Propellant Tanks Read More: Https://Arc.Aiaa.Org/Doi/Abs/10.2514/6.2019-2177, Pedro Llanos

Pedro J. Llanos (www.AstronauticsLlanos.com)

The phenomenon of sloshing is a substantial challenge in propellant management, particularly in reduced gravity where surface tension-driven flows result in large slosh amplitudes and relatively long decay time scales. Propellant Management Devices (PMDs) such as the rigid baffles and elastomeric membranes are often employed to counteract motion of the free surface. In the present study, we investigate an active PMD that utilizes a free-floating membrane that, under an applied static magnetic field, becomes rigid and suppresses slosh. This semi-rigid structural layer can thereby replace bulky baffle structures and reduce the overall weight of the tank. In this paper, the ...


3d Textile Preforms And Composites For Aircraft Strcutures: A Review, Abbasali Saboktakin 2019 University of sistan and baluchestan, Zahedan, Iran

3d Textile Preforms And Composites For Aircraft Strcutures: A Review, Abbasali Saboktakin

International Journal of Aviation, Aeronautics, and Aerospace

Over the last decades, the development of 3D textile composites has been driven the structures developed to overcome disadvantages of 2D laminates such as the needs of reducing fabrication cost, increasing through-thickness mechanical properties, and improving impact damage tolerance. 3D woven, stitched, knitted and braided preforms have been used as composites reinforcement for these types of composites. In this paper, advantages and disadvantages of each of them have been comprehensively discussed. The fabric architects and their specification in particular stitched preforms and their deformation mode for aerospace applications have been reviewed. Exact insight into various types of damage in textile ...


A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong 2019 Old Dominion University

A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong

Electrical & Computer Engineering Faculty Publications

Perovskite solar cells have achieved photo-conversion efficiencies greater than 20%, making them a promising candidate as an emerging solar cell technology. While perovskite solar cells are expected to eventually compete with existing silicon-based solar cells on the market, their long-term stability has become a major bottleneck. In particular, perovskite films are found to be very sensitive to external factors such as air, UV light, light soaking, thermal stress and others. Among these stressors, light, oxygen and moisture-induced degradation can be slowed by integrating barrier or interface layers within the device architecture. However, the most representative perovskite absorber material, CH3 ...


The Effects Of Silica On The Properties Of Vitreous Enamels, Signo Tadeu Dos Reis, Mike Koenigstein, Liang Fan, Genda Chen, Luka Pavic, Andrea Mogus-Milankovic 2018 Missouri University of Science and Technology

The Effects Of Silica On The Properties Of Vitreous Enamels, Signo Tadeu Dos Reis, Mike Koenigstein, Liang Fan, Genda Chen, Luka Pavic, Andrea Mogus-Milankovic

Materials Science and Engineering Faculty Research & Creative Works

Ground coat enamels for low carbon steel that contain silica as a mill addition have been developed to study the changes of their properties. Acid-resistant commercial enamel where silica addition was varied from 0 to 10.0 wt % was used for this investigation. The effects of the addition on the corrosion resistance, thermal properties, electrical properties, and mechanical adherence of the enamel to low carbon steel were studied. The corrosion resistance of the steel enameled coupons was tested using a salt spray (fog) apparatus for time periods reaching 168 h at room temperature. It was found that, although the density ...


Modeling And Simulation Of The Thermoforming Process In Thermoplastic-Matrix Composite Materials, Philip M. Bean 2018 University of Maine

Modeling And Simulation Of The Thermoforming Process In Thermoplastic-Matrix Composite Materials, Philip M. Bean

Electronic Theses and Dissertations

Thermoplastic-matrix composite materials have unique advantages over traditional thermosets including faster processing, improved fracture toughness, and recyclability. These and other benefits have caused increasing interest in the use of these materials in both aerospace and automotive industries. Due to the differences in behavior, these materials require a different type of manufacturing process to thermoset matrix composites. This manufacturing process generally involves using pre manufactured tape-layers. These layers, containing both thermoplastic-matrix and fiber-reinforcement, are aligned to the desired orientation, and stacked up into a “tailored blank” using an automated tape layup machine. They are then heated to the thermoplastic melting temperature ...


Digital Commons powered by bepress