Pub Date : 2024-10-11DOI: 10.1038/s43246-024-00660-8
Rémi Blinder, Yuliya Mindarava, Thai Hien Tran, Ali Momenzadeh, Sen Yang, Petr Siyushev, Hitoshi Sumiya, Kenji Tamasaku, Taito Osaka, Norio Morishita, Haruki Takizawa, Shinobu Onoda, Hideyuki Hara, Fedor Jelezko, Jörg Wrachtrup, Junichi Isoya
With their optical addressability of individual spins and long coherence time, nitrogen-vacancy (NV) centers in diamond are often called “atom-like solid spin-defects”. As observed with trapped atomic ions, quantum interference mediated by indistinguishable photons was demonstrated between remote NV centers. In high sensitivity DC magnetometry at room temperature, NV ensembles are potentially rivaling with alkali-atom vapor cells. However, local strain induces center-to-center variation of both optical and spin transitions of NV centers. Therefore, advanced engineering of diamond growth toward crystalline perfection is demanded. Here, we report on the synthesis of high-quality HPHT (high-pressure, high-temperature) crystals, demonstrating a small inhomogeneous broadening of the spin transitions, of T2* = 1.28 μs, approaching the limit for crystals with natural 13C abundance, that we determine as T2* = 1.48 μs. The contribution from strain and local charges to the inhomogeneous broadening is lowered to ~17 kHz full width at half maximum for NV ensemble within a > 10 mm3 volume. Looking at optical transitions in low nitrogen crystals, we examine the variation of zero-phonon-line optical transition frequencies at low temperatures, showing a strain contribution below 2 GHz for a large fraction of single NV centers. Nitrogen-vacancy centers in diamond offer a promising platform for quantum applications but their optical and spin properties can be hampered by imperfections of the host crystal. Here, nitrogen-vacancy centers are created in high-pressure high-temperature diamond of high crystalline quality, demonstrating a small inhomogeneous broadening of the spin and optical transitions.
{"title":"Reducing inhomogeneous broadening of spin and optical transitions of nitrogen-vacancy centers in high-pressure, high-temperature diamond","authors":"Rémi Blinder, Yuliya Mindarava, Thai Hien Tran, Ali Momenzadeh, Sen Yang, Petr Siyushev, Hitoshi Sumiya, Kenji Tamasaku, Taito Osaka, Norio Morishita, Haruki Takizawa, Shinobu Onoda, Hideyuki Hara, Fedor Jelezko, Jörg Wrachtrup, Junichi Isoya","doi":"10.1038/s43246-024-00660-8","DOIUrl":"10.1038/s43246-024-00660-8","url":null,"abstract":"With their optical addressability of individual spins and long coherence time, nitrogen-vacancy (NV) centers in diamond are often called “atom-like solid spin-defects”. As observed with trapped atomic ions, quantum interference mediated by indistinguishable photons was demonstrated between remote NV centers. In high sensitivity DC magnetometry at room temperature, NV ensembles are potentially rivaling with alkali-atom vapor cells. However, local strain induces center-to-center variation of both optical and spin transitions of NV centers. Therefore, advanced engineering of diamond growth toward crystalline perfection is demanded. Here, we report on the synthesis of high-quality HPHT (high-pressure, high-temperature) crystals, demonstrating a small inhomogeneous broadening of the spin transitions, of T2* = 1.28 μs, approaching the limit for crystals with natural 13C abundance, that we determine as T2* = 1.48 μs. The contribution from strain and local charges to the inhomogeneous broadening is lowered to ~17 kHz full width at half maximum for NV ensemble within a > 10 mm3 volume. Looking at optical transitions in low nitrogen crystals, we examine the variation of zero-phonon-line optical transition frequencies at low temperatures, showing a strain contribution below 2 GHz for a large fraction of single NV centers. Nitrogen-vacancy centers in diamond offer a promising platform for quantum applications but their optical and spin properties can be hampered by imperfections of the host crystal. Here, nitrogen-vacancy centers are created in high-pressure high-temperature diamond of high crystalline quality, demonstrating a small inhomogeneous broadening of the spin and optical transitions.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-10"},"PeriodicalIF":7.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00660-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415433","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 : 2024-10-11DOI: 10.1038/s43246-024-00659-1
Sunmi Kim, Leonid V. Abdurakhimov, Duong Pham, Wei Qiu, Hirotaka Terai, Sahel Ashhab, Shiro Saito, Taro Yamashita, Kouichi Semba
Conventional superconducting flux qubits require the application of a precisely tuned magnetic field to set the operation point at half a flux quantum through the qubit loop, which complicates the on-chip integration of this type of device. It has been proposed that by inducing a π-phase shift in the superconducting order parameter using a precisely controlled nanoscale-thickness superconductor/ferromagnet/superconductor Josephson junction, commonly referred to as π-junction, it is possible to realize a flux qubit operating at zero magnetic flux. Here, we report the realization of a zero-flux-biased flux qubit based on three NbN/AlN/NbN Josephson junctions and a NbN/PdNi/NbN ferromagnetic π-junction. The qubit lifetime is in the microsecond range, which we argue is limited by quasiparticle excitations in the metallic ferromagnet layer. Our results pave the way for developing quantum coherent devices, including qubits and sensors, that utilize the interplay between ferromagnetism and superconductivity. Conventional superconducting flux qubits require a finely tuned magnetic field to operate, hindering their on-chip integration. Here, ferromagnetic Josephson junctions with a π-phase shift in the superconducting order parameter allow the realization of a flux qubit operating at zero magnetic field.
{"title":"Superconducting flux qubit with ferromagnetic Josephson π-junction operating at zero magnetic field","authors":"Sunmi Kim, Leonid V. Abdurakhimov, Duong Pham, Wei Qiu, Hirotaka Terai, Sahel Ashhab, Shiro Saito, Taro Yamashita, Kouichi Semba","doi":"10.1038/s43246-024-00659-1","DOIUrl":"10.1038/s43246-024-00659-1","url":null,"abstract":"Conventional superconducting flux qubits require the application of a precisely tuned magnetic field to set the operation point at half a flux quantum through the qubit loop, which complicates the on-chip integration of this type of device. It has been proposed that by inducing a π-phase shift in the superconducting order parameter using a precisely controlled nanoscale-thickness superconductor/ferromagnet/superconductor Josephson junction, commonly referred to as π-junction, it is possible to realize a flux qubit operating at zero magnetic flux. Here, we report the realization of a zero-flux-biased flux qubit based on three NbN/AlN/NbN Josephson junctions and a NbN/PdNi/NbN ferromagnetic π-junction. The qubit lifetime is in the microsecond range, which we argue is limited by quasiparticle excitations in the metallic ferromagnet layer. Our results pave the way for developing quantum coherent devices, including qubits and sensors, that utilize the interplay between ferromagnetism and superconductivity. Conventional superconducting flux qubits require a finely tuned magnetic field to operate, hindering their on-chip integration. Here, ferromagnetic Josephson junctions with a π-phase shift in the superconducting order parameter allow the realization of a flux qubit operating at zero magnetic field.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-7"},"PeriodicalIF":7.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00659-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415423","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}
Hydrogen embrittlement (HE) is a major issue for the mechanical integrity of high-strength alloys exposed to hydrogen-rich environments, with diffusion and trapping of hydrogen being critical phenomena. Here, the role of microstructure on hydrogen diffusion, trapping and embrittlement in additively manufactured (AM) and wrought Inconel 718 is compared, revealing the key role played by dislocation cells. Trapping behaviour in hydrogen-saturated alloys is analysed by thermal desorption spectroscopy and numerical simulations. A high density of hydrogen traps in cell walls, attributed to dense dislocations and Laves phases, are responsible for the local accumulation of hydrogen, causing significant loss in strength, and triggering cracking along dislocation cell walls. The influential role of dislocation cells alters fracture behaviour from intergranular in the wrought alloy to intragranular for the AM alloy, due to the large proportion of dislocation cells in AM alloys. In addition, the cellular network of dislocations accelerates hydrogen diffusion, enabling faster and deeper penetration of hydrogen in the AM alloy. These results indicate that the higher HE susceptibility of nickel superalloys is intrinsically associated with the interaction of hydrogen with dislocation walls. Hydrogen embrittlement is a major issue in alloys used in hydrogen-rich environments, such as in jet engines. In this study, the presence of a large number of dislocation cells in an additively manufactured nickel superalloy promotes hydrogen diffusion and fracture, as compared to a wrought alloy with fewer dislocation cells.
氢脆（HE）是暴露在富氢环境中的高强度合金机械完整性的一个主要问题，其中氢的扩散和捕获是关键现象。本文比较了微观结构对添加制造（AM）和锻造 Inconel 718 中氢扩散、捕集和脆化的作用，揭示了位错电池所起的关键作用。通过热解吸光谱和数值模拟分析了氢饱和合金中的捕获行为。由于致密位错和 Laves 相的存在，晶胞壁中的氢陷阱密度很高，导致氢在局部积聚，造成强度显著下降，并引发沿位错晶胞壁的裂纹。位错晶胞的影响作用改变了断裂行为，从锻造合金的晶间断裂转变为 AM 合金的晶内断裂，这是由于 AM 合金中位错晶胞所占比例较大。此外，位错蜂窝网络加速了氢扩散，使氢在 AM 合金中的渗透更快、更深。这些结果表明，镍超合金较高的氢脆敏感性与氢与位错壁的相互作用有内在联系。氢脆是在喷气发动机等富氢环境中使用的合金的一个主要问题。在这项研究中，与位错单元较少的锻造合金相比，在添加制造的镍超合金中存在大量位错单元会促进氢扩散和断裂。
{"title":"Influence of dislocation cells on hydrogen embrittlement in wrought and additively manufactured Inconel 718","authors":"Claudia-Tatiana Santos Maldonado, Alfredo Zafra, Emilio Martínez Pañeda, Paul Sandmann, Roberto Morana, Minh-Son Pham","doi":"10.1038/s43246-024-00654-6","DOIUrl":"10.1038/s43246-024-00654-6","url":null,"abstract":"Hydrogen embrittlement (HE) is a major issue for the mechanical integrity of high-strength alloys exposed to hydrogen-rich environments, with diffusion and trapping of hydrogen being critical phenomena. Here, the role of microstructure on hydrogen diffusion, trapping and embrittlement in additively manufactured (AM) and wrought Inconel 718 is compared, revealing the key role played by dislocation cells. Trapping behaviour in hydrogen-saturated alloys is analysed by thermal desorption spectroscopy and numerical simulations. A high density of hydrogen traps in cell walls, attributed to dense dislocations and Laves phases, are responsible for the local accumulation of hydrogen, causing significant loss in strength, and triggering cracking along dislocation cell walls. The influential role of dislocation cells alters fracture behaviour from intergranular in the wrought alloy to intragranular for the AM alloy, due to the large proportion of dislocation cells in AM alloys. In addition, the cellular network of dislocations accelerates hydrogen diffusion, enabling faster and deeper penetration of hydrogen in the AM alloy. These results indicate that the higher HE susceptibility of nickel superalloys is intrinsically associated with the interaction of hydrogen with dislocation walls. Hydrogen embrittlement is a major issue in alloys used in hydrogen-rich environments, such as in jet engines. In this study, the presence of a large number of dislocation cells in an additively manufactured nickel superalloy promotes hydrogen diffusion and fracture, as compared to a wrought alloy with fewer dislocation cells.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-13"},"PeriodicalIF":7.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00654-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415409","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 : 2024-10-09DOI: 10.1038/s43246-024-00667-1
Guixin Hou, Shengyu Zhu, Hui Tan, Wenyuan Chen, Jiao Chen, Qichun Sun, Juanjuan Chen, Jun Cheng, Peixuan Li, William Yi Wang, Jun Yang, Weimin Liu
Achieving near-zero-wear remains a major challenge in mechanical engineering and material science. Current ultra-low wear materials are typically developed based on the self-consumption strategy. Here, we demonstrate a new self-repairing approach to achieve near-zero-wear. We find that the WB4-βB/WC tribo-pair has a low wear rate of 10−8 mm3 N−1 m−1 in low vacuum conditions, under a maximum Hertzian contact stress of 2.23 GPa over 1 × 105 friction cycles. Additionally, we observe an abnormal wear phenomenon after 5 × 104 friction cycles, characterized by an increase in the dimensions of the tribo-pair. This near-zero-wear mechanism is attributed to the synergistic action of the super-hard WB4-βB substrate and the self-repairing tribo-oxide layer. This research provides a new approach for advancing wear-resistant materials and enhancing material longevity. Expanding the range of ultra-low-wear material systems would benefit a number of applications. Here, near-zero-wear is reported in a WB4-βB/WC tribo-pair system, attributed to surface self-repair in a certain wear regime.
{"title":"Near-zero-wear with super-hard WB4 and a self-repairing tribo-chemical layer","authors":"Guixin Hou, Shengyu Zhu, Hui Tan, Wenyuan Chen, Jiao Chen, Qichun Sun, Juanjuan Chen, Jun Cheng, Peixuan Li, William Yi Wang, Jun Yang, Weimin Liu","doi":"10.1038/s43246-024-00667-1","DOIUrl":"10.1038/s43246-024-00667-1","url":null,"abstract":"Achieving near-zero-wear remains a major challenge in mechanical engineering and material science. Current ultra-low wear materials are typically developed based on the self-consumption strategy. Here, we demonstrate a new self-repairing approach to achieve near-zero-wear. We find that the WB4-βB/WC tribo-pair has a low wear rate of 10−8 mm3 N−1 m−1 in low vacuum conditions, under a maximum Hertzian contact stress of 2.23 GPa over 1 × 105 friction cycles. Additionally, we observe an abnormal wear phenomenon after 5 × 104 friction cycles, characterized by an increase in the dimensions of the tribo-pair. This near-zero-wear mechanism is attributed to the synergistic action of the super-hard WB4-βB substrate and the self-repairing tribo-oxide layer. This research provides a new approach for advancing wear-resistant materials and enhancing material longevity. Expanding the range of ultra-low-wear material systems would benefit a number of applications. Here, near-zero-wear is reported in a WB4-βB/WC tribo-pair system, attributed to surface self-repair in a certain wear regime.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-10"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00667-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415396","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 : 2024-10-09DOI: 10.1038/s43246-024-00657-3
Arthur Mantel, Berthold Stöger, Alexander Prado-Roller, Hidetsugu Shiozawa
Methods to grow large crystals provide the foundation for material science and technology. Here we demonstrate single crystal homoepitaxy of a metal-organic framework (MOF) built of zinc, acetate and terephthalate ions, that encapsulate arrays of octahedral zinc dimethyl sulfoxide (DMSO) complex cations within its one-dimensional (1D) channels. The three-dimensional framework is built of two-dimensional Zn-terephthalate square lattices interconnected by anionic acetate pillars through diatomic zinc nodes. The charge of the anionic framework is neutralized by the 1D arrays of $${{rm{Zn}}}{({{rm{DMSO}}})}_{6}^{2+}$$ cations that fill every second 1D channel of the framework. It is demonstrated that the repeatable and scalable epitaxy allows square cuboids of this charge-transfer MOF to grow stepwise to sizes in the centimeter range. The continuous growth with no size limits can be attributed to the ionic nature of the anionic framework with cationic 1D molecular fillers. These findings pave the way for epitaxial growth of bulk crystals of MOFs. Bulk crystal growth of metal-organic frameworks remains a challenge. Here, a single crystal of a metal-organic framework is grown homoepitaxially in the centimeter range, assisted by the ionic nature of the anionic framework with cationic 1D molecular fillers.
{"title":"Host-guest charge transfer for scalable single crystal epitaxy of a metal-organic framework","authors":"Arthur Mantel, Berthold Stöger, Alexander Prado-Roller, Hidetsugu Shiozawa","doi":"10.1038/s43246-024-00657-3","DOIUrl":"10.1038/s43246-024-00657-3","url":null,"abstract":"Methods to grow large crystals provide the foundation for material science and technology. Here we demonstrate single crystal homoepitaxy of a metal-organic framework (MOF) built of zinc, acetate and terephthalate ions, that encapsulate arrays of octahedral zinc dimethyl sulfoxide (DMSO) complex cations within its one-dimensional (1D) channels. The three-dimensional framework is built of two-dimensional Zn-terephthalate square lattices interconnected by anionic acetate pillars through diatomic zinc nodes. The charge of the anionic framework is neutralized by the 1D arrays of $${{rm{Zn}}}{({{rm{DMSO}}})}_{6}^{2+}$$ cations that fill every second 1D channel of the framework. It is demonstrated that the repeatable and scalable epitaxy allows square cuboids of this charge-transfer MOF to grow stepwise to sizes in the centimeter range. The continuous growth with no size limits can be attributed to the ionic nature of the anionic framework with cationic 1D molecular fillers. These findings pave the way for epitaxial growth of bulk crystals of MOFs. Bulk crystal growth of metal-organic frameworks remains a challenge. Here, a single crystal of a metal-organic framework is grown homoepitaxially in the centimeter range, assisted by the ionic nature of the anionic framework with cationic 1D molecular fillers.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-6"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00657-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415429","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 : 2024-10-09DOI: 10.1038/s43246-024-00627-9
Hyemin Jung, Seunghyun Lee, Xiao Jin, Yifan Liu, Theodore. J. Ronningen, Christopher. H. Grein, John. P. R. David, Sanjay Krishna
The rising concentration of greenhouse gases, especially methane and carbon dioxide, is driving global temperature increases and exacerbating the climate crisis. Monitoring these gases requires detectors that operate in the extended short-wavelength infrared range (~2.4 µm), covering methane (1.65 µm) and carbon dioxide (2.05 µm) wavelengths. Here, we present a high-performance linear mode avalanche photodetector (APD) with an InGaAs/GaAsSb type-II superlattice absorber and an AlGaAsSb multiplier, matched to InP substrates. This APD achieves a room temperature gain of 178, an external quantum efficiency of 3560% at 2 µm, low excess noise (less than 2 at gains below 20), and a small temperature coefficient of breakdown (7.58 mV/K·µm). These results indicate that a manufacturable semiconductor material-based APD could significantly advance high-sensitivity receivers for greenhouse gas monitoring, potentially enabling their commercial production and widespread use. Photodetectors for monitoring greenhouse gas emissions must cover the extended short-wavelength infrared range. Here, antimonide-based materials on a InP substrate enable a high-performance avalanche photodiode with detectivity beyond 2 µm wavelength.
{"title":"Low excess noise and high quantum efficiency avalanche photodiodes for beyond 2 µm wavelength detection","authors":"Hyemin Jung, Seunghyun Lee, Xiao Jin, Yifan Liu, Theodore. J. Ronningen, Christopher. H. Grein, John. P. R. David, Sanjay Krishna","doi":"10.1038/s43246-024-00627-9","DOIUrl":"10.1038/s43246-024-00627-9","url":null,"abstract":"The rising concentration of greenhouse gases, especially methane and carbon dioxide, is driving global temperature increases and exacerbating the climate crisis. Monitoring these gases requires detectors that operate in the extended short-wavelength infrared range (~2.4 µm), covering methane (1.65 µm) and carbon dioxide (2.05 µm) wavelengths. Here, we present a high-performance linear mode avalanche photodetector (APD) with an InGaAs/GaAsSb type-II superlattice absorber and an AlGaAsSb multiplier, matched to InP substrates. This APD achieves a room temperature gain of 178, an external quantum efficiency of 3560% at 2 µm, low excess noise (less than 2 at gains below 20), and a small temperature coefficient of breakdown (7.58 mV/K·µm). These results indicate that a manufacturable semiconductor material-based APD could significantly advance high-sensitivity receivers for greenhouse gas monitoring, potentially enabling their commercial production and widespread use. Photodetectors for monitoring greenhouse gas emissions must cover the extended short-wavelength infrared range. Here, antimonide-based materials on a InP substrate enable a high-performance avalanche photodiode with detectivity beyond 2 µm wavelength.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-7"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00627-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415430","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 : 2024-10-09DOI: 10.1038/s43246-024-00655-5
Alexander Feichtmayer, Max Boleininger, Johann Riesch, Daniel R. Mason, Luca Reali, Till Höschen, Maximilian Fuhr, Thomas Schwarz-Selinger, Rudolf Neu, Sergei L. Dudarev
The occurrence of high stress concentrations in reactor components is a still intractable phenomenon encountered in fusion reactor design. Here, we observe and quantitatively model a non-linear high-dose radiation mediated microstructure evolution effect that facilitates fast stress relaxation in the most challenging low-temperature limit. In situ observations of a tensioned tungsten wire exposed to a high-energy ion beam show that internal stress of up to 2 GPa relaxes within minutes, with the extent and time-scale of relaxation accurately predicted by a parameter-free multiscale model informed by atomistic simulations. As opposed to conventional notions of radiation creep, the effect arises from the self-organisation of nanoscale crystal defects, athermally coalescing into extended polarized dislocation networks that compensate and alleviate the external stress. The creep behavior of actively cooled alloys exposed to neutron irradiation in fusion reactors is expected to critically affect the operation of reactor components. Here, experiments and simulations of a 16 μm thick tungsten wire exposed to low-temperature irradiation reveal stress relaxation rates far exceeding those associated with thermal creep.
{"title":"Fast low-temperature irradiation creep driven by athermal defect dynamics","authors":"Alexander Feichtmayer, Max Boleininger, Johann Riesch, Daniel R. Mason, Luca Reali, Till Höschen, Maximilian Fuhr, Thomas Schwarz-Selinger, Rudolf Neu, Sergei L. Dudarev","doi":"10.1038/s43246-024-00655-5","DOIUrl":"10.1038/s43246-024-00655-5","url":null,"abstract":"The occurrence of high stress concentrations in reactor components is a still intractable phenomenon encountered in fusion reactor design. Here, we observe and quantitatively model a non-linear high-dose radiation mediated microstructure evolution effect that facilitates fast stress relaxation in the most challenging low-temperature limit. In situ observations of a tensioned tungsten wire exposed to a high-energy ion beam show that internal stress of up to 2 GPa relaxes within minutes, with the extent and time-scale of relaxation accurately predicted by a parameter-free multiscale model informed by atomistic simulations. As opposed to conventional notions of radiation creep, the effect arises from the self-organisation of nanoscale crystal defects, athermally coalescing into extended polarized dislocation networks that compensate and alleviate the external stress. The creep behavior of actively cooled alloys exposed to neutron irradiation in fusion reactors is expected to critically affect the operation of reactor components. Here, experiments and simulations of a 16 μm thick tungsten wire exposed to low-temperature irradiation reveal stress relaxation rates far exceeding those associated with thermal creep.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00655-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415415","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 : 2024-10-09DOI: 10.1038/s43246-024-00643-9
Zexiong Qiu, Jiale Liu, Chuanzhou Han, Chaoyang Wang, Junwei Xiang, Ziwei Zheng, Minhao Xia, Yang Zhou, Anyi Mei, Hongwei Han
Hole-conductor-free printable mesoscopic perovskite solar cells (p-MPSCs) have attracted widespread attention for their low cost, up-scalability, and exceptional stability. However, the high defect density of perovskite and the absence of interfacial barrier layer between perovskite and carbon electrode cause profound open-circuit voltage (VOC) loss, which results in uncompetitive power conversion efficiency (PCE). Herein, an anion-cation synergy of decylammonium sulfate (DA2SO4) is utilized for suppressing VOC loss of p-MPSCs via a facile post-treatment method. DA+ cations transform the perovskite adjacent to carbon electrode into wide-bandgap 2D perovskite for blocking electrons, while the SO42− anions interact with undercoordinated lead centers for reducing defect density. As a result, the modified device delivers an enhanced PCE from 17.78% to 19.59%, with an improved VOC from 0.98 V to 1.06 V. Meanwhile, the modified device without any encapsulation exhibits excellent moisture stability with the PCE remained almost 99% of the initial value after 528 h aging in 75% RH air at room temperature. Open-circuit voltage loss is an issue faced by hole-conductor-free printable mesoscopic perovskite solar cells. Here, a facile decylammonium sulfate post-treatment reduces the voltage loss via an anion-cation synergy, and increases the power conversion efficiency from 17.8% to 19.6%.
{"title":"Decylammonium sulfate post-treatment for efficient hole-conductor-free printable perovskite solar cells with reduced voltage loss","authors":"Zexiong Qiu, Jiale Liu, Chuanzhou Han, Chaoyang Wang, Junwei Xiang, Ziwei Zheng, Minhao Xia, Yang Zhou, Anyi Mei, Hongwei Han","doi":"10.1038/s43246-024-00643-9","DOIUrl":"10.1038/s43246-024-00643-9","url":null,"abstract":"Hole-conductor-free printable mesoscopic perovskite solar cells (p-MPSCs) have attracted widespread attention for their low cost, up-scalability, and exceptional stability. However, the high defect density of perovskite and the absence of interfacial barrier layer between perovskite and carbon electrode cause profound open-circuit voltage (VOC) loss, which results in uncompetitive power conversion efficiency (PCE). Herein, an anion-cation synergy of decylammonium sulfate (DA2SO4) is utilized for suppressing VOC loss of p-MPSCs via a facile post-treatment method. DA+ cations transform the perovskite adjacent to carbon electrode into wide-bandgap 2D perovskite for blocking electrons, while the SO42− anions interact with undercoordinated lead centers for reducing defect density. As a result, the modified device delivers an enhanced PCE from 17.78% to 19.59%, with an improved VOC from 0.98 V to 1.06 V. Meanwhile, the modified device without any encapsulation exhibits excellent moisture stability with the PCE remained almost 99% of the initial value after 528 h aging in 75% RH air at room temperature. Open-circuit voltage loss is an issue faced by hole-conductor-free printable mesoscopic perovskite solar cells. Here, a facile decylammonium sulfate post-treatment reduces the voltage loss via an anion-cation synergy, and increases the power conversion efficiency from 17.8% to 19.6%.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-8"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00643-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415391","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 : 2024-10-09DOI: 10.1038/s43246-024-00650-w
Yury Gogotsi is a pioneer of the burgeoning field of 2D MXenes. Here he offers his insight on the history of MXene development, promising applications and what he is excited about.
{"title":"Discussing MXenes with Yury Gogotsi","authors":"","doi":"10.1038/s43246-024-00650-w","DOIUrl":"10.1038/s43246-024-00650-w","url":null,"abstract":"Yury Gogotsi is a pioneer of the burgeoning field of 2D MXenes. Here he offers his insight on the history of MXene development, promising applications and what he is excited about.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-3"},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00650-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415431","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 : 2024-10-08DOI: 10.1038/s43246-024-00649-3
Thies Jansen, Ekaterina Kochetkova, Anna Isaeva, Alexander Brinkman, Chuan Li
Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. In this work, we investigate the transport properties of the intrinsic magnetic topological insulator MnBi2Te4 (MBT). In normal transport measurements, we observe the presence of chiral edge channels, though with deviations from perfect quantization due to factors such as non-uniform thickness, domain structures, and the presence of quasi-helical edge states. Subsequently, we fabricate superconducting junctions using niobium leads on MBT exfoliated flakes, which show an onset of supercurrent with clear Josephson coupling. The interference patterns in the superconducting junctions reveal interesting asymmetries, suggesting changes in the magnetic ordering of the MBT flakes under small applied magnetic fields. Moreover, the modulation of the critical current by magnetic field reveals a SQUID-like pattern, suggesting the presence of supercurrent through the quasi-helical edge states. Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. Here, the intrinsic and Josephson junction transport properties of magnetic topological insulator MnBi2Te4 are investigated, revealing superconducting interference patterns that suggest the presence of supercurrent through quasi-helical edge states.
{"title":"Josephson coupling across magnetic topological insulator MnBi2Te4","authors":"Thies Jansen, Ekaterina Kochetkova, Anna Isaeva, Alexander Brinkman, Chuan Li","doi":"10.1038/s43246-024-00649-3","DOIUrl":"10.1038/s43246-024-00649-3","url":null,"abstract":"Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. In this work, we investigate the transport properties of the intrinsic magnetic topological insulator MnBi2Te4 (MBT). In normal transport measurements, we observe the presence of chiral edge channels, though with deviations from perfect quantization due to factors such as non-uniform thickness, domain structures, and the presence of quasi-helical edge states. Subsequently, we fabricate superconducting junctions using niobium leads on MBT exfoliated flakes, which show an onset of supercurrent with clear Josephson coupling. The interference patterns in the superconducting junctions reveal interesting asymmetries, suggesting changes in the magnetic ordering of the MBT flakes under small applied magnetic fields. Moreover, the modulation of the critical current by magnetic field reveals a SQUID-like pattern, suggesting the presence of supercurrent through the quasi-helical edge states. Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. Here, the intrinsic and Josephson junction transport properties of magnetic topological insulator MnBi2Te4 are investigated, revealing superconducting interference patterns that suggest the presence of supercurrent through quasi-helical edge states.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":" ","pages":"1-9"},"PeriodicalIF":7.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00649-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415395","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：