Ultrafast control of ferroelectricity and magnetism by light is essential for future development in multiple functioning devices. Here, we demonstrate that the intense and ultrafast photo-modulation of the electric dipole can be realized by photocarrier injection into a multiferroic BiFeO3 thin film using optical pump-probe and second harmonic generation measurements. Results of ultrafast electron diffraction with <100 fs time resolution and theoretical study reveal that the localized photocarrier strongly couples with the lattice structure and becomes the origin for the observed sudden change in the electric dipole. In addition, the subsequent structural dynamics involve a strong oscillation with a frequency of ~3.3 THz despite a poor structural symmetry change. Based on a theoretical calculation, this oscillation can be attributed to an unexpectedly softened new phonon mode generated by mixing essential two phonon modes governing the multiferroic (ferroelectric and antiferromagnetic) nature of BiFeO3 in the ground state due to strong coupling with a localized photocarrier. The comprehensive study shows that injection of the localized photocarrier strongly coupled with the lattice vibration mode can simultaneously realize the ultrafast switching of electric dipoles and magnetic interaction at once, even at room temperature, without modifying the long-range lattice structure. Ultrafast control of ferroelectricity and magnetism by light is essential for multifunctional devices. Here, photocarrier injection into multiferroic BiFeO3 thin films can simultaneously realize the ultrafast switching of electric dipoles and magnetic interaction due to the strong coupling between the localized photocarrier and lattice vibrations.
{"title":"Photocontrol of ferroelectricity in multiferroic BiFeO3 via structural modification coupled with photocarrier","authors":"Kou Takubo, Atsushi Ono, Shunsuke Ueno, Samiran Banu, Hongwu Yu, Kaito En-ya, Ryota Nishimori, Makoto Kuwahara, Toru Asaka, Kei Maeda, Daiki Ono, Keita Ozawa, Takuma Itoh, Kei Shigematsu, Masaki Azuma, Tadahiko Ishikawa, Yoichi Okimoto, Masaki Hada, Shin-ya Koshihara","doi":"10.1038/s43246-024-00698-8","DOIUrl":"10.1038/s43246-024-00698-8","url":null,"abstract":"Ultrafast control of ferroelectricity and magnetism by light is essential for future development in multiple functioning devices. Here, we demonstrate that the intense and ultrafast photo-modulation of the electric dipole can be realized by photocarrier injection into a multiferroic BiFeO3 thin film using optical pump-probe and second harmonic generation measurements. Results of ultrafast electron diffraction with <100 fs time resolution and theoretical study reveal that the localized photocarrier strongly couples with the lattice structure and becomes the origin for the observed sudden change in the electric dipole. In addition, the subsequent structural dynamics involve a strong oscillation with a frequency of ~3.3 THz despite a poor structural symmetry change. Based on a theoretical calculation, this oscillation can be attributed to an unexpectedly softened new phonon mode generated by mixing essential two phonon modes governing the multiferroic (ferroelectric and antiferromagnetic) nature of BiFeO3 in the ground state due to strong coupling with a localized photocarrier. The comprehensive study shows that injection of the localized photocarrier strongly coupled with the lattice vibration mode can simultaneously realize the ultrafast switching of electric dipoles and magnetic interaction at once, even at room temperature, without modifying the long-range lattice structure. Ultrafast control of ferroelectricity and magnetism by light is essential for multifunctional devices. Here, photocarrier injection into multiferroic BiFeO3 thin films can simultaneously realize the ultrafast switching of electric dipoles and magnetic interaction due to the strong coupling between the localized photocarrier and lattice vibrations.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00698-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142762989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1038/s43246-024-00705-y
Alireza Yaghoubi, Robert Patterson, Xiaojing Hao
Ferroelectricity in solar cells is credited with a multitude of benefits, including improved charge carrier separation and higher than band gap device voltages, however most ferroelectrics are wide-gap materials that generate very little photocurrent. Some halide perovskites are ferroelectric, but they suffer from degradation, despite their otherwise excellent performance. Recently, BaZrS3, a chalcogenide perovskite has received attention due to its optimal band gap, non-toxicity, and superior stability. The ground state of BaZrS3 is reportedly a GdFeO3-type distorted perovskite (space group Pnma). Here, using first-principle calculations, we show that the polar Pna21 is thermodynamically as stable as Pnma. This new phase is weakly ferroelectric, exhibiting a net polarization of 0.27 µC/cm2 and a d33 piezoelectric coefficient of only ~1 pm/V. Under strain, the interplay between out-of-plane and in-plane octahedral tilts amplifies spontaneous polarization, spin splitting, and large polaron radii. These exotic traits are comparable to those of the popular halide perovskites. Ferroelectricity in solar cells can improve charge carrier separation and provide higher than bandgap device voltages. Here, first-principles calculations in strained BaZrS3 reveal ferroelectricity and exotic properties akin to halide perovskites for photovoltaics applications.
{"title":"Exotic ferroelectricity in strained BaZrS3 chalcogenide perovskite for photovoltaics","authors":"Alireza Yaghoubi, Robert Patterson, Xiaojing Hao","doi":"10.1038/s43246-024-00705-y","DOIUrl":"10.1038/s43246-024-00705-y","url":null,"abstract":"Ferroelectricity in solar cells is credited with a multitude of benefits, including improved charge carrier separation and higher than band gap device voltages, however most ferroelectrics are wide-gap materials that generate very little photocurrent. Some halide perovskites are ferroelectric, but they suffer from degradation, despite their otherwise excellent performance. Recently, BaZrS3, a chalcogenide perovskite has received attention due to its optimal band gap, non-toxicity, and superior stability. The ground state of BaZrS3 is reportedly a GdFeO3-type distorted perovskite (space group Pnma). Here, using first-principle calculations, we show that the polar Pna21 is thermodynamically as stable as Pnma. This new phase is weakly ferroelectric, exhibiting a net polarization of 0.27 µC/cm2 and a d33 piezoelectric coefficient of only ~1 pm/V. Under strain, the interplay between out-of-plane and in-plane octahedral tilts amplifies spontaneous polarization, spin splitting, and large polaron radii. These exotic traits are comparable to those of the popular halide perovskites. Ferroelectricity in solar cells can improve charge carrier separation and provide higher than bandgap device voltages. Here, first-principles calculations in strained BaZrS3 reveal ferroelectricity and exotic properties akin to halide perovskites for photovoltaics applications.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00705-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142762951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1038/s43246-024-00704-z
Connor E. Slone, Veronika Mazánová, Punit Kumar, David H. Cook, Milan Heczko, Qin Yu, Bryan Crossman, Easo P. George, Michael J. Mills, Robert O. Ritchie
Engineering materials exhibit an undesirable tradeoff between strength and resistance to crack propagation (fracture toughness). Here we demonstrate how this tradeoff can be circumvented by thermo-mechanical processing that produces a partially recrystallized, heterogeneous microstructure. An equimolar CrCoNi alloy was forged at room temperature (298 K) to produce high densities of three-dimensional crystallographic defect networks. Post-deformation heat treatments caused localized recrystallization that resulted in a bimodal microstructure with hard, non-recrystallized grains and soft, recrystallized grains. In this condition, the yield strength at 298 K is 2.75x the values previously obtained for the same alloy in the fully recrystallized state while the fracture toughness remains the same. The yield strength is further enhanced at 77 K without compromising the fracture toughness. This outstanding strength-toughness combination at 77 K exceeds those reported for other metallic materials and appears to result from the composite nature of the microstructure with non-recrystallized grains providing strength and recrystallized grains enabling plasticity that dissipates stresses during crack propagation. Our findings indicate that by tuning the degree of recrystallization through thermomechanical processing techniques, it will be possible to further expand the envelope bounding the strength and toughness of a range of structural metals at engineering component scales. Research into engineering alloys is often driven by the need to simultaneously improve strength and toughness. Here, an equimolar CrCoNi medium-entropy alloy achieves an almost three times increase in yield strength without sacrificing toughness, attributed to a partially recrystallized microstructure.
{"title":"Partially recrystallized microstructures expand the strength-toughness envelope of CrCoNi medium-entropy alloy","authors":"Connor E. Slone, Veronika Mazánová, Punit Kumar, David H. Cook, Milan Heczko, Qin Yu, Bryan Crossman, Easo P. George, Michael J. Mills, Robert O. Ritchie","doi":"10.1038/s43246-024-00704-z","DOIUrl":"10.1038/s43246-024-00704-z","url":null,"abstract":"Engineering materials exhibit an undesirable tradeoff between strength and resistance to crack propagation (fracture toughness). Here we demonstrate how this tradeoff can be circumvented by thermo-mechanical processing that produces a partially recrystallized, heterogeneous microstructure. An equimolar CrCoNi alloy was forged at room temperature (298 K) to produce high densities of three-dimensional crystallographic defect networks. Post-deformation heat treatments caused localized recrystallization that resulted in a bimodal microstructure with hard, non-recrystallized grains and soft, recrystallized grains. In this condition, the yield strength at 298 K is 2.75x the values previously obtained for the same alloy in the fully recrystallized state while the fracture toughness remains the same. The yield strength is further enhanced at 77 K without compromising the fracture toughness. This outstanding strength-toughness combination at 77 K exceeds those reported for other metallic materials and appears to result from the composite nature of the microstructure with non-recrystallized grains providing strength and recrystallized grains enabling plasticity that dissipates stresses during crack propagation. Our findings indicate that by tuning the degree of recrystallization through thermomechanical processing techniques, it will be possible to further expand the envelope bounding the strength and toughness of a range of structural metals at engineering component scales. Research into engineering alloys is often driven by the need to simultaneously improve strength and toughness. Here, an equimolar CrCoNi medium-entropy alloy achieves an almost three times increase in yield strength without sacrificing toughness, attributed to a partially recrystallized microstructure.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-10"},"PeriodicalIF":7.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00704-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142762978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1038/s43246-024-00701-2
Dai-Nam Le, Pablo Rodriguez-Lopez, Lilia M. Woods
The strong coupling between electromagnetic fields and lattice oscillations in piezoelectric materials gives rise to phonon polariton excitations. Such quasiparticles are important in modulating the ubiquitous Casimir force. Here by utilizing the generalized Born-Huang hydrodynamics model exemplified in SiC, three types of phonons are studied: longitudinal optical phonon, transverse optical phonon and phonon polariton. The Fresnel reflection coefficients for the piezoelectric composed of semi-infinite substrates or thin films are then obtained by taking into account the phonon-electromagnetic coupling. The Casimir interaction, calculated via a generalized Lifshitz approach, is examined to highlight the interplay between different types of phonon modes and electromagnetic excitations. Our study shows that piezoelectrics emerge as materials where this ubiquitous force can be controlled via phonon properties. Different types of surface phonon polaritons associated with structural polytypes may also be distinguished through the Casimir interaction. Strong coupling between electromagnetic fields and lattice oscillations in piezoelectric materials gives rise to interesting phonon polariton excitations. Here, the role of these modes in modulating the Casimir force of piezoelectric plates is investigated theoretically, expanding the range of materials where the Casimir interaction can be detected and controlled.
{"title":"Phonon-assisted Casimir interactions between piezoelectric materials","authors":"Dai-Nam Le, Pablo Rodriguez-Lopez, Lilia M. Woods","doi":"10.1038/s43246-024-00701-2","DOIUrl":"10.1038/s43246-024-00701-2","url":null,"abstract":"The strong coupling between electromagnetic fields and lattice oscillations in piezoelectric materials gives rise to phonon polariton excitations. Such quasiparticles are important in modulating the ubiquitous Casimir force. Here by utilizing the generalized Born-Huang hydrodynamics model exemplified in SiC, three types of phonons are studied: longitudinal optical phonon, transverse optical phonon and phonon polariton. The Fresnel reflection coefficients for the piezoelectric composed of semi-infinite substrates or thin films are then obtained by taking into account the phonon-electromagnetic coupling. The Casimir interaction, calculated via a generalized Lifshitz approach, is examined to highlight the interplay between different types of phonon modes and electromagnetic excitations. Our study shows that piezoelectrics emerge as materials where this ubiquitous force can be controlled via phonon properties. Different types of surface phonon polaritons associated with structural polytypes may also be distinguished through the Casimir interaction. Strong coupling between electromagnetic fields and lattice oscillations in piezoelectric materials gives rise to interesting phonon polariton excitations. Here, the role of these modes in modulating the Casimir force of piezoelectric plates is investigated theoretically, expanding the range of materials where the Casimir interaction can be detected and controlled.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-7"},"PeriodicalIF":7.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00701-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanical properties of polyurethane ionogels prepared by UV light-curing are usually inferior to those of conventional polyurethanes. Highly entangled polymer chain networks with chemical crosslinking can potentially address this problem. Here, we prepare ionogels (PU-HRs) using UV curing technology with esterified rutin as a cross-linking agent. After optimization of the preparation process by response surface methodology, we obtain PU-HRs with a tensile strength of 34.96 MPa and toughness as high as 88.11 MJ m−3 (1.26-fold higher than that of silk from the silkworm, Bombyx mori (70 MJ m−3)). The high strength and toughness of PU-HR are mainly attributed to the three-dimensional cross-linked network structure formed by the “rigid-flexible” esterified rutin, the micro-phase separation structure between the soft-chain fragments, and the hard-chain fragments that form stable interfacial regions. These ionogels have great prospects in sunscreen coating applications, such as for sunscreen umbrellas and automotive or architectural sunscreen glass. Polyurethane ionogels can be made with UV light curing but suffer from low mechanical properties compared to conventional polyurethane. Here, robust UV light curable ionogels are made by using prepolymers containing carbon-carbon double bonds as monomers which cross-links to form entangled polymer networks.
{"title":"Ultra-tough light-curing ionogels for UV shielding","authors":"Zeyu Zhang, Dejun Peng, Xueyan Shang, Xin Zhao, Shixue Ren, Jiuyin Pang, Shujun Li","doi":"10.1038/s43246-024-00702-1","DOIUrl":"10.1038/s43246-024-00702-1","url":null,"abstract":"The mechanical properties of polyurethane ionogels prepared by UV light-curing are usually inferior to those of conventional polyurethanes. Highly entangled polymer chain networks with chemical crosslinking can potentially address this problem. Here, we prepare ionogels (PU-HRs) using UV curing technology with esterified rutin as a cross-linking agent. After optimization of the preparation process by response surface methodology, we obtain PU-HRs with a tensile strength of 34.96 MPa and toughness as high as 88.11 MJ m−3 (1.26-fold higher than that of silk from the silkworm, Bombyx mori (70 MJ m−3)). The high strength and toughness of PU-HR are mainly attributed to the three-dimensional cross-linked network structure formed by the “rigid-flexible” esterified rutin, the micro-phase separation structure between the soft-chain fragments, and the hard-chain fragments that form stable interfacial regions. These ionogels have great prospects in sunscreen coating applications, such as for sunscreen umbrellas and automotive or architectural sunscreen glass. Polyurethane ionogels can be made with UV light curing but suffer from low mechanical properties compared to conventional polyurethane. Here, robust UV light curable ionogels are made by using prepolymers containing carbon-carbon double bonds as monomers which cross-links to form entangled polymer networks.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-12"},"PeriodicalIF":7.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00702-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1038/s43246-024-00699-7
Kaushalendra K. Singh, Akane Wakai, Atieh Moridi
Operando X-ray techniques have enabled real-time observation and analysis of metal additive manufacturing (AM) processes, providing invaluable insights into solidification mechanisms and melt pool behavior. In this perspective, we present the current state of the art in X-ray diffraction and imaging studies of laser-based metal AM processes, specifically Directed Energy Deposition and Powder Bed Fusion. We explore various data analyses that can be performed with time-resolved data, including phase identification, microstructural evolution, tracking melt pool behavior, and defect formation. Additionally, we highlight the limitations of existing operando studies and provide an outlook on overcoming these challenges. Additive manufacturing has emerged as a powerful approach for achieving properties that are not possible in conventionally processed alloys. This Perspective provides a state-of-art overview of the use of operando x-ray techniques for understanding solidification dynamics and melt pool behavior in additive processes.
{"title":"Advancements in operando X-ray techniques for metal additive manufacturing","authors":"Kaushalendra K. Singh, Akane Wakai, Atieh Moridi","doi":"10.1038/s43246-024-00699-7","DOIUrl":"10.1038/s43246-024-00699-7","url":null,"abstract":"Operando X-ray techniques have enabled real-time observation and analysis of metal additive manufacturing (AM) processes, providing invaluable insights into solidification mechanisms and melt pool behavior. In this perspective, we present the current state of the art in X-ray diffraction and imaging studies of laser-based metal AM processes, specifically Directed Energy Deposition and Powder Bed Fusion. We explore various data analyses that can be performed with time-resolved data, including phase identification, microstructural evolution, tracking melt pool behavior, and defect formation. Additionally, we highlight the limitations of existing operando studies and provide an outlook on overcoming these challenges. Additive manufacturing has emerged as a powerful approach for achieving properties that are not possible in conventionally processed alloys. This Perspective provides a state-of-art overview of the use of operando x-ray techniques for understanding solidification dynamics and melt pool behavior in additive processes.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00699-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1038/s43246-024-00700-3
Lei Wang, Venkatesh Naidu Nerella, Dianmo Li, Yuying Zhang, Bin Ma, Egor Ivaniuk, Junyi Zhang, Xiaohong Zhu, Jianhua Yan, Viktor Mechtcherine, Daniel C. W. Tsang
Three-dimensional (3D) concrete printing is a revolutionary technology in the construction industry. Here we show that climate-positive biochar is a carbon-negative additive for decreasing the carbon footprint of 3D printable concrete, while enhancing its performance. As biochar enhanced the effective water-to-binder ratio and served as a substrate for hydrates, the polymerization of hydrates increased in biochar-augmented concrete. The incorporation of 2 wt% biochar enhanced the structural build-up rate of fresh mixtures by 22% at 40 min. The 3D printing tests demonstrated that biochar improved the pumpability and extrudability of mixtures at the initial 20 min, and enhanced the buildability of 3D printed concretes at the after 40 min. The carbon footprint of 3D printable concrete was reduced by 8.3% through incorporating 2 wt% biochar. Thus, we developed a desirable biochar-augmented mixture for 3D concrete printing. Future field-scale application will make substantial contribution to the attainment of carbon emission reduction. 3D printing of concrete is promising for the manufacture of bespoke structures, but the high cement component leads to large carbon dioxide emissions. Here, climate-positive biochar is shown to decrease the carbon footprint of 3D printed concrete, while improving its pumpability, extrudability, and buildability
{"title":"Biochar-augmented climate-positive 3D printable concrete","authors":"Lei Wang, Venkatesh Naidu Nerella, Dianmo Li, Yuying Zhang, Bin Ma, Egor Ivaniuk, Junyi Zhang, Xiaohong Zhu, Jianhua Yan, Viktor Mechtcherine, Daniel C. W. Tsang","doi":"10.1038/s43246-024-00700-3","DOIUrl":"10.1038/s43246-024-00700-3","url":null,"abstract":"Three-dimensional (3D) concrete printing is a revolutionary technology in the construction industry. Here we show that climate-positive biochar is a carbon-negative additive for decreasing the carbon footprint of 3D printable concrete, while enhancing its performance. As biochar enhanced the effective water-to-binder ratio and served as a substrate for hydrates, the polymerization of hydrates increased in biochar-augmented concrete. The incorporation of 2 wt% biochar enhanced the structural build-up rate of fresh mixtures by 22% at 40 min. The 3D printing tests demonstrated that biochar improved the pumpability and extrudability of mixtures at the initial 20 min, and enhanced the buildability of 3D printed concretes at the after 40 min. The carbon footprint of 3D printable concrete was reduced by 8.3% through incorporating 2 wt% biochar. Thus, we developed a desirable biochar-augmented mixture for 3D concrete printing. Future field-scale application will make substantial contribution to the attainment of carbon emission reduction. 3D printing of concrete is promising for the manufacture of bespoke structures, but the high cement component leads to large carbon dioxide emissions. Here, climate-positive biochar is shown to decrease the carbon footprint of 3D printed concrete, while improving its pumpability, extrudability, and buildability","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-10"},"PeriodicalIF":7.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00700-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1038/s43246-024-00697-9
Sami Kaappa, Suvi Santa-aho, Mari Honkanen, Minnamari Vippola, Lasse Laurson
Defects, impurities, and embedded particles in ferromagnetic materials are long known to be responsible for the Barkhausen effect due to the jerky field-driven motion of domain walls and have more recently been shown to play a role also in domain wall dynamics in nanoscale ferromagnetic structures used in spintronics devices. Simulating the magnetic domain wall dynamics in the micromagnetic framework offers a straightforward route to study such systems and phenomena. However, the related work in the past suffers from material imperfections being introduced without proper physical foundation. Here, we implement dislocation stress fields in micromagnetic simulations through the induced anisotropy fields by inverse magnetostriction. The effects of individual dislocations on domain wall dynamics in thin films of different Fe surface lattice planes are characterized numerically. As a demonstration of the applicability of the implementation, we consider disorder fields due to randomly positioned dislocations with different densities, and study the avalanche-like transient approach towards the depinning transition of a domain wall driven by a slowly increasing external magnetic field. Simulating the magnetic domain wall dynamics in ferromagnetic materials is crucial for designing spintronics devices, but including material imperfections is often challenging. Here, the effects of individual dislocations on domain wall dynamics in thin films of iron is investigated by micromagnetic simulations.
{"title":"Magnetic domain walls interacting with dislocations in micromagnetic simulations","authors":"Sami Kaappa, Suvi Santa-aho, Mari Honkanen, Minnamari Vippola, Lasse Laurson","doi":"10.1038/s43246-024-00697-9","DOIUrl":"10.1038/s43246-024-00697-9","url":null,"abstract":"Defects, impurities, and embedded particles in ferromagnetic materials are long known to be responsible for the Barkhausen effect due to the jerky field-driven motion of domain walls and have more recently been shown to play a role also in domain wall dynamics in nanoscale ferromagnetic structures used in spintronics devices. Simulating the magnetic domain wall dynamics in the micromagnetic framework offers a straightforward route to study such systems and phenomena. However, the related work in the past suffers from material imperfections being introduced without proper physical foundation. Here, we implement dislocation stress fields in micromagnetic simulations through the induced anisotropy fields by inverse magnetostriction. The effects of individual dislocations on domain wall dynamics in thin films of different Fe surface lattice planes are characterized numerically. As a demonstration of the applicability of the implementation, we consider disorder fields due to randomly positioned dislocations with different densities, and study the avalanche-like transient approach towards the depinning transition of a domain wall driven by a slowly increasing external magnetic field. Simulating the magnetic domain wall dynamics in ferromagnetic materials is crucial for designing spintronics devices, but including material imperfections is often challenging. Here, the effects of individual dislocations on domain wall dynamics in thin films of iron is investigated by micromagnetic simulations.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-11"},"PeriodicalIF":7.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00697-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hypercrosslinked polymers (HCPs) have gained attention as promising materials for separation membranes due to their abundant porosity, low cost, ease of preparation, and excellent stability. Here, we demonstrate an interfacial-assisted polymerization approach to prepare continuous HCP membranes at room temperature. The method demonstrates versatility in constructing HCP membranes using various precursors, including small molecules and polymers. Specifically, the HCP membranes prepared using benzene as the monomer exhibit controllable thickness and a remarkable Brunauer-Emmett-Teller surface area of up to 855 m2 g−1. Leveraging physical size sieving and electrostatic interaction, the fabricated benzene-based membranes effectively reject small anionic dye molecules, such as Congo Red, Acid Fuchsin, and Methyl Orange, achieving rejection rates exceeding 93% while maintaining a high-water flux of up to 55 L m−2 h−1 bar−1. This study shows a versatile approach for the design of HCP membranes capable of efficiently separating mixtures containing small molecules. Hypercrosslinked polymers are promising materials for separation membranes due to their low cost and high porosity. Here, continuous hypercrosslinked polymer membranes are prepared using interfacial polymerization that effectively rejects small dye molecules with high water flux.
{"title":"Hypercrosslinked polymer membranes via interfacial polymerization for organic dye separations","authors":"Qingyin Li, Shuqing Li, Caimei Yu, Zhen Zhan, Guang Cheng, Bien Tan, Shijie Ren","doi":"10.1038/s43246-024-00668-0","DOIUrl":"10.1038/s43246-024-00668-0","url":null,"abstract":"Hypercrosslinked polymers (HCPs) have gained attention as promising materials for separation membranes due to their abundant porosity, low cost, ease of preparation, and excellent stability. Here, we demonstrate an interfacial-assisted polymerization approach to prepare continuous HCP membranes at room temperature. The method demonstrates versatility in constructing HCP membranes using various precursors, including small molecules and polymers. Specifically, the HCP membranes prepared using benzene as the monomer exhibit controllable thickness and a remarkable Brunauer-Emmett-Teller surface area of up to 855 m2 g−1. Leveraging physical size sieving and electrostatic interaction, the fabricated benzene-based membranes effectively reject small anionic dye molecules, such as Congo Red, Acid Fuchsin, and Methyl Orange, achieving rejection rates exceeding 93% while maintaining a high-water flux of up to 55 L m−2 h−1 bar−1. This study shows a versatile approach for the design of HCP membranes capable of efficiently separating mixtures containing small molecules. Hypercrosslinked polymers are promising materials for separation membranes due to their low cost and high porosity. Here, continuous hypercrosslinked polymer membranes are prepared using interfacial polymerization that effectively rejects small dye molecules with high water flux.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00668-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1038/s43246-024-00635-9
Manabu Sato, Juba Bouaziz, Shuntaro Sumita, Shingo Kobayashi, Ikuma Tateishi, Stefan Blügel, Akira Furusaki, Motoaki Hirayama
Topological semimetals, known for their intriguing properties arising from band degeneracies, have garnered significant attention. However, the discovery of a material realization and the detailed characterization of spinless Dirac semimetals have not yet been accomplished. Here, we propose from first-principles calculations that the RE8CoX3 group (RE = rare earth elements, X = Al, Ga, or In) contains ideal spinless Dirac semimetals whose Fermi surfaces are fourfold degenerate band-crossing points (without including spin degeneracy). Despite the lack of space inversion symmetry in these materials, Dirac points are formed on the rotation-symmetry axis due to accidental degeneracies of two bands corresponding to different 2-dimensional irreducible representations of the C6v group. We also investigate, through first-principles calculations and effective model analysis, various phase transitions caused by lattice distortion or elemental substitutions from the Dirac semimetal phase to distinct topological semimetallic phases such as nonmagnetic linked-nodal-line and Weyl semimetals (characterized by the second Stiefel–Whitney class) and ferromagnetic Weyl semimetals. Band degeneracies at the Fermi level in topological semimetals are sources of intriguing interference effects between electronic states around the degeneracy points. Here, the RE8CoX3 compounds, with RE = rare-earth and X = Al, Ga, or In, are proposed as realizations of ideal spinless Dirac semimetals hosting the fourfold degenerate band-crossing points without the spin degrees of freedom.
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