D. Goll, Marius Boettle, Joerg Buschbeck, R. Loeffler, Gerhard Schneider
Ce substitution of Nd in FeNdB sintered magnets is very interesting for reasons of resource efficiency, sustainability and costs. However, the magnetic properties of high Ce‐content magnets are poor. This is mainly due to the lower values of intrinsic magnetic properties of Fe14Ce2B compared to Fe14Nd2B as well as the Laves phase Fe2Ce, which is formed in the grain boundaries and forms flat aggregates for higher Ce‐content. In this paper, sintered magnets with 75 at% degree of substitution of the composition Fe70.9‐[(Ce1‐xLax)0.75Nd0.25]18.8‐B5.8‐M4.5 (M = Co, Ti, Al, Ga, Cu, 0 ≤ × ≤ 0.3) are produced and analyzed. It is shown that a new rare earth rich grain boundary phase is formed adding La and that the Laves phase fraction can be reduced by up to 85%. With increasing La content, the remanence and Curie temperature increase and the temperature coefficient of Hc improves. A coercivity, remanence and maximum energy density of up to µ0Hc = 0.74 T, Jr = 0.98 T and (BH)max = 139.9 kJ/m3 have been achieved.This article is protected by copyright. All rights reserved.
由于资源效率、可持续性和成本等原因，在 FeNdB 烧结磁体中用 Ce 替代 Nd 非常有趣。然而，高铈含量磁体的磁性能较差。这主要是由于与 Fe14Nd2B 相比，Fe14Ce2B 的固有磁性能值较低，以及拉维斯相 Fe2Ce 在晶界中形成，并在较高 Ce 含量时形成扁平聚集体。本文生产并分析了成分为 Fe70.9-[(Ce1-xLax)0.75Nd0.25]18.8-B5.8-M4.5 （M = Co、Ti、Al、Ga、Cu，0 ≤ × ≤ 0.3）、替代度为 75% 的烧结磁体。结果表明，加入 La 后会形成新的富稀土晶界相，Laves 相分数最多可减少 85%。随着 La 含量的增加，剩磁和居里温度上升，Hc 的温度系数提高。矫顽力、剩磁和最大能量密度分别达到μ0Hc = 0.74 T、Jr = 0.98 T和(BH)max = 139.9 kJ/m3。本文受版权保护。
{"title":"High Cerium content Fe‐Ce‐Nd‐B sintered magnets with high coercivity","authors":"D. Goll, Marius Boettle, Joerg Buschbeck, R. Loeffler, Gerhard Schneider","doi":"10.1002/pssr.202400151","DOIUrl":"https://doi.org/10.1002/pssr.202400151","url":null,"abstract":"Ce substitution of Nd in FeNdB sintered magnets is very interesting for reasons of resource efficiency, sustainability and costs. However, the magnetic properties of high Ce‐content magnets are poor. This is mainly due to the lower values of intrinsic magnetic properties of Fe14Ce2B compared to Fe14Nd2B as well as the Laves phase Fe2Ce, which is formed in the grain boundaries and forms flat aggregates for higher Ce‐content. In this paper, sintered magnets with 75 at% degree of substitution of the composition Fe70.9‐[(Ce1‐xLax)0.75Nd0.25]18.8‐B5.8‐M4.5 (M = Co, Ti, Al, Ga, Cu, 0 ≤ × ≤ 0.3) are produced and analyzed. It is shown that a new rare earth rich grain boundary phase is formed adding La and that the Laves phase fraction can be reduced by up to 85%. With increasing La content, the remanence and Curie temperature increase and the temperature coefficient of Hc improves. A coercivity, remanence and maximum energy density of up to µ0Hc = 0.74 T, Jr = 0.98 T and (BH)max = 139.9 kJ/m3 have been achieved.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The concept of photonic crystals has recently been extended to the time domain and attracted great interest. Unfortunately, realizing photonic time crystals is a challenging task due to the practical difficulty in modulating dielectric constants with large modulation depth. This problem can be resolved by using graphene, the conductivity of which is tunable with significantly large contrast. In this report, graphene plasmonic time crystals, as a new kind of photonic time crystals in atomically thin two‐dimensional material, are proposed and their optical properties are investigated. Their bandstructures are analytically calculated and the propagations of graphene plasmons in temporal crystalline structures are numerically evaluated. Periodically driven by temporally modulating the Fermi energy, graphene plasmons exhibit in‐gap amplification and defects‐immune topological edge states, revealing the nature as plasmonic time crystals. Graphene plasmonic time crystals will be realized soon after this proposal due to the possibility of modulating its conductivity with large contrast by simple electrical gating.This article is protected by copyright. All rights reserved.
{"title":"Graphene plasmonic time crystals","authors":"Kwang-Hyon Kim, O. Kang-Hyok","doi":"10.1002/pssr.202400116","DOIUrl":"https://doi.org/10.1002/pssr.202400116","url":null,"abstract":"The concept of photonic crystals has recently been extended to the time domain and attracted great interest. Unfortunately, realizing photonic time crystals is a challenging task due to the practical difficulty in modulating dielectric constants with large modulation depth. This problem can be resolved by using graphene, the conductivity of which is tunable with significantly large contrast. In this report, graphene plasmonic time crystals, as a new kind of photonic time crystals in atomically thin two‐dimensional material, are proposed and their optical properties are investigated. Their bandstructures are analytically calculated and the propagations of graphene plasmons in temporal crystalline structures are numerically evaluated. Periodically driven by temporally modulating the Fermi energy, graphene plasmons exhibit in‐gap amplification and defects‐immune topological edge states, revealing the nature as plasmonic time crystals. Graphene plasmonic time crystals will be realized soon after this proposal due to the possibility of modulating its conductivity with large contrast by simple electrical gating.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141108624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Xiang, Hao Tang, Zihao Zhu, Bo Pang, Tingjun Zhou, H. Zhan, Junyong Kang, Yongliang Zhou
Electronic properties of intrinsic ZnO, N doped ZnO and Al‐N co‐doped ZnO of both hexagonal wurtzite (HW) and zinc blende (ZB) structures were investigated by first‐principles calculations. Both N doped ZB‐ZnO and N doped HW‐ZnO achieve p‐type transition by the introduction of N‐2p states, forming shallow acceptor levels above the valence band. However, the positive impurity formation energy implied the difficulty and instability of N‐doped ZnO. In Al‐N co‐doped ZnO, the Al elements compensate the p‐type doping effect, but partially enhance the solubility of N. Furthermore, the comparison of the electronic properties between HW‐ZnO and ZB‐ZnO, indicated that the ZB structure favors the achieving of p‐type doping.This article is protected by copyright. All rights reserved.
通过第一性原理计算研究了本征氧化锌、掺杂 N 的氧化锌和 Al-N 共掺杂的六方沃特兹（HW）和锌混合物（ZB）结构氧化锌的电子特性。掺杂了氮的 ZB-ZnO 和掺杂了氮的 HW-ZnO 都通过引入 N-2p 态实现了 p 型转变，在价带上方形成了浅受主层。然而，正杂质形成能意味着 N 掺杂 ZnO 的难度和不稳定性。此外，HW-ZnO 和 ZB-ZnO 的电子特性比较表明，ZB 结构有利于实现 p 型掺杂。本文受版权保护。
{"title":"First‐principles Study of the Al‐N co‐doped Zincblende ZnO","authors":"Yang Xiang, Hao Tang, Zihao Zhu, Bo Pang, Tingjun Zhou, H. Zhan, Junyong Kang, Yongliang Zhou","doi":"10.1002/pssr.202400104","DOIUrl":"https://doi.org/10.1002/pssr.202400104","url":null,"abstract":"Electronic properties of intrinsic ZnO, N doped ZnO and Al‐N co‐doped ZnO of both hexagonal wurtzite (HW) and zinc blende (ZB) structures were investigated by first‐principles calculations. Both N doped ZB‐ZnO and N doped HW‐ZnO achieve p‐type transition by the introduction of N‐2p states, forming shallow acceptor levels above the valence band. However, the positive impurity formation energy implied the difficulty and instability of N‐doped ZnO. In Al‐N co‐doped ZnO, the Al elements compensate the p‐type doping effect, but partially enhance the solubility of N. Furthermore, the comparison of the electronic properties between HW‐ZnO and ZB‐ZnO, indicated that the ZB structure favors the achieving of p‐type doping.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141110403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tobias Okker, R. Glatthaar, S. Seren, Giso Hahn, Barbara Terheiden
In recent years the mechanism of carrier transport through a junction of polycrystalline silicon (poly‐Si) on an interface oxide has been extensively discussed for passivating contacts of crystalline silicon‐based solar cells fabricated along the well‐established high temperature route. In the fired passivating contact (FPC) approach, no extended crystallization is foreseen which also modifies the properties of the junction. Here, we investigate atmospheric pressure chemical vapor deposited (APCVD), phosphorus‐doped (n) poly‐Si, which is annealed at different temperatures and durations following the FPC approach. Symmetric lifetime samples show the passivation potential of the FPC approach with implied open circuit voltages (iVOC) values of up to 736 mV. Temperature‐dependent specific contact resistivity measurements applying the transfer length method on differently grown interface oxides are used to identify tunneling or pinhole transport, or a combination of both. It is found that a transition from tunneling to pinhole transport surprisingly takes place already for annealing durations of a few seconds and is primarily impacted by annealing temperature instead of duration. Pinhole magnification studies via tetramethylammonium etching and scanning electron microscopy confirm the existence of pinholes in the interfacial oxides.This article is protected by copyright. All rights reserved.
{"title":"Charge carrier transport mechanism through different oxides for (n) poly‐Si/SiOx fired passivating contacts","authors":"Tobias Okker, R. Glatthaar, S. Seren, Giso Hahn, Barbara Terheiden","doi":"10.1002/pssr.202400099","DOIUrl":"https://doi.org/10.1002/pssr.202400099","url":null,"abstract":"In recent years the mechanism of carrier transport through a junction of polycrystalline silicon (poly‐Si) on an interface oxide has been extensively discussed for passivating contacts of crystalline silicon‐based solar cells fabricated along the well‐established high temperature route. In the fired passivating contact (FPC) approach, no extended crystallization is foreseen which also modifies the properties of the junction. Here, we investigate atmospheric pressure chemical vapor deposited (APCVD), phosphorus‐doped (n) poly‐Si, which is annealed at different temperatures and durations following the FPC approach. Symmetric lifetime samples show the passivation potential of the FPC approach with implied open circuit voltages (iVOC) values of up to 736 mV. Temperature‐dependent specific contact resistivity measurements applying the transfer length method on differently grown interface oxides are used to identify tunneling or pinhole transport, or a combination of both. It is found that a transition from tunneling to pinhole transport surprisingly takes place already for annealing durations of a few seconds and is primarily impacted by annealing temperature instead of duration. Pinhole magnification studies via tetramethylammonium etching and scanning electron microscopy confirm the existence of pinholes in the interfacial oxides.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141114639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two‐dimensional (2D) transition metal dichalcogenides (TMDs) have attracted intensive interests for its unique electronic, optical, and thermal properties. Doping is necessary to expand the application. However, the stability of doped materials has been overlooked. This study focuses on the stability of monolayer‐doped MoS2 with different vanadium (V) concentrations. It provides a quantitative assessment of the etching results. Findings indicate that the stability of MoS2 under different etching atmospheres follows the series of lightly doped MoS2 (LD), pristine MoS2 (PR), moderately doped MoS2 (MD), and highly doped MoS2 (HD). Our research indicates that the stability of the material is linked to the bonding energy of cations and anions, as well as the amount of lattice distortion, which competes with one another. Low levels of V doping do not lead to significant lattice distortion, and the binding energy between sulfur (S) and V surpasses that of molybdenum (Mo), which is the primary factor. Excessive doping results in lattice distortion, which leads to a multitude of defects and a reduction in durability. This work is important for guiding the assessment of the reliability, the protection of degradation, and application scenarios of TMDs.This article is protected by copyright. All rights reserved.
{"title":"Stability of Vanadium Doped Transition Metal Dichalcogenides under Etching Atmosphere","authors":"Sunwen Zhao, R. Xiao, Yuhan Feng, Chuang Tian, Jiawen Liu, Guanghui Yu","doi":"10.1002/pssr.202400128","DOIUrl":"https://doi.org/10.1002/pssr.202400128","url":null,"abstract":"Two‐dimensional (2D) transition metal dichalcogenides (TMDs) have attracted intensive interests for its unique electronic, optical, and thermal properties. Doping is necessary to expand the application. However, the stability of doped materials has been overlooked. This study focuses on the stability of monolayer‐doped MoS2 with different vanadium (V) concentrations. It provides a quantitative assessment of the etching results. Findings indicate that the stability of MoS2 under different etching atmospheres follows the series of lightly doped MoS2 (LD), pristine MoS2 (PR), moderately doped MoS2 (MD), and highly doped MoS2 (HD). Our research indicates that the stability of the material is linked to the bonding energy of cations and anions, as well as the amount of lattice distortion, which competes with one another. Low levels of V doping do not lead to significant lattice distortion, and the binding energy between sulfur (S) and V surpasses that of molybdenum (Mo), which is the primary factor. Excessive doping results in lattice distortion, which leads to a multitude of defects and a reduction in durability. This work is important for guiding the assessment of the reliability, the protection of degradation, and application scenarios of TMDs.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141124346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper discusses the advantages of AlN low‐temperature interface protective layer (LT‐IPL) prepared by sputtering epitaxy for the fabrication of AlN/Al0.5Ga0.5N/AlN multichannel device structures. The study found that the use of LT‐IPL enhances the AlN/AlGaN interface surface morphology and reduces AlN/Al0.5Ga0.5N/AlN multichannel structure misfit dislocations. This approach results in a coherent four‐channel AlN/AlGaN/AlN structure with considerably improved crystallinity. Moreover, consistent with predictions from one‐dimensional simulations, reductions in sheet resistance are inversely proportional to the number of channels. These advancements are pivotal for the development of sophisticated AlN/AlGaN/AlN multichannel structures which are tailored for applications that require low resistance and high voltage.This article is protected by copyright. All rights reserved.
{"title":"Pulsed sputtering epitaxy of coherent AlN/Al0.5Ga0.5N/AlN multichannel structures","authors":"Takao Kozaka, Ryota Maeda, Kohei Ueno, Hiroshi Fujioka","doi":"10.1002/pssr.202400142","DOIUrl":"https://doi.org/10.1002/pssr.202400142","url":null,"abstract":"This paper discusses the advantages of AlN low‐temperature interface protective layer (LT‐IPL) prepared by sputtering epitaxy for the fabrication of AlN/Al0.5Ga0.5N/AlN multichannel device structures. The study found that the use of LT‐IPL enhances the AlN/AlGaN interface surface morphology and reduces AlN/Al0.5Ga0.5N/AlN multichannel structure misfit dislocations. This approach results in a coherent four‐channel AlN/AlGaN/AlN structure with considerably improved crystallinity. Moreover, consistent with predictions from one‐dimensional simulations, reductions in sheet resistance are inversely proportional to the number of channels. These advancements are pivotal for the development of sophisticated AlN/AlGaN/AlN multichannel structures which are tailored for applications that require low resistance and high voltage.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140969794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kyumin Park, Byeongho Park, Kanghoon Seo, Hyekyeong Jang, Myung Gwan Hahm, Youngseok Oh
Molybdenum disulfide (MoS2) is a promising alternative to graphite anodes in battery materials. Therefore, it is critical to scrutinize their structural stability and charge storage capacity during battery operation. In this study, freestanding electrodes consisting of MoS2‐incorporated carbon nanotube aerogels (MSCA) were fabricated using a simple yet scalable hydrothermal method, as used in lithium‐ion batteries. The outer nitrogen‐doped graphitic carbon (NGr) layers support efficient charge transport, even under a substantial compressive environment, and improve the structural integrity, showing significant improvements in battery performance, such as a high rate capacity of 820 mAh g−1 at the current density of 5 A g−1 and 94% capacity retention after 170 cycles (1170 mAh g−1 at 1 A g−1 after 170 cycles), even in the absence of polymer binders and conductive additives. The resulting NGr/MoS2/Single‐Walled Carbon Nanotubes (SWCNT) freestanding electrodes have great potential to increase the volumetric and gravimetric energy density of batteries.This article is protected by copyright. All rights reserved.
二硫化钼（MoS2）是一种替代石墨阳极的电池材料，前景广阔。因此，仔细研究其结构稳定性和电池工作期间的电荷存储能力至关重要。在本研究中，采用一种简单而可扩展的水热法制造了由 MoS2-掺杂碳纳米管气凝胶（MSCA）组成的独立电极，该方法也用于锂离子电池。掺氮石墨碳（NGr）外层支持高效的电荷传输，即使在强压环境下也是如此，并改善了结构的完整性，显著提高了电池性能，例如，即使在没有聚合物粘合剂和导电添加剂的情况下，电流密度为 5 A g-1 时的高倍率容量为 820 mAh g-1，循环 170 次后的容量保持率为 94%（循环 170 次后，电流密度为 1 A g-1 时的容量保持率为 1170 mAh g-1）。由此产生的 NGr/MoS2/Single-Walled Carbon Nanotubes (SWCNT) 独立电极在提高电池的体积和重力能量密度方面具有巨大潜力。本文受版权保护。
{"title":"Mechanically and Electrically Stable Hybrid Aerogels as Free‐Standing Anodes for High‐Capacity Lithium‐Ion Battery","authors":"Kyumin Park, Byeongho Park, Kanghoon Seo, Hyekyeong Jang, Myung Gwan Hahm, Youngseok Oh","doi":"10.1002/pssr.202400118","DOIUrl":"https://doi.org/10.1002/pssr.202400118","url":null,"abstract":"Molybdenum disulfide (MoS2) is a promising alternative to graphite anodes in battery materials. Therefore, it is critical to scrutinize their structural stability and charge storage capacity during battery operation. In this study, freestanding electrodes consisting of MoS2‐incorporated carbon nanotube aerogels (MSCA) were fabricated using a simple yet scalable hydrothermal method, as used in lithium‐ion batteries. The outer nitrogen‐doped graphitic carbon (NGr) layers support efficient charge transport, even under a substantial compressive environment, and improve the structural integrity, showing significant improvements in battery performance, such as a high rate capacity of 820 mAh g−1 at the current density of 5 A g−1 and 94% capacity retention after 170 cycles (1170 mAh g−1 at 1 A g−1 after 170 cycles), even in the absence of polymer binders and conductive additives. The resulting NGr/MoS2/Single‐Walled Carbon Nanotubes (SWCNT) freestanding electrodes have great potential to increase the volumetric and gravimetric energy density of batteries.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140977486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The magnetoelectric (ME) sensor, a new and promising type of magnetic field sensor with ultrahigh sensitivity. However, there are few reports on the research of real‐time measurement system which can promote its practical application. In this study, a novel real‐time measuring approach for weak AC magnetic fields at relatively low frequency was proposed using Metglas/PZT‐5B magnetoelectric sensors. The system mainly consists of an oscilloscope, a signal generator and a program developed with LabVIEW programming. Real‐time measurement of relatively low frequency magnetic fields have been achieved by using frequency up‐conversion methods,simultaneously display the frequency and magnitude of the magnetic field. As a result, the real‐time measurement system was able to detect a weak AC magnetic field as low as 0.1 nT@1Hz, which is promising to push the ME sensor to practical application.This article is protected by copyright. All rights reserved.
磁电（ME）传感器是一种新型、有前途的磁场传感器，具有超高灵敏度。然而，有关实时测量系统的研究报道却很少，而这种研究却能促进其实际应用。本研究利用 Metglas/PZT-5B 磁电传感器，提出了一种新型的实时测量方法，用于测量频率相对较低的弱交流磁场。该系统主要由示波器、信号发生器和 LabVIEW 编程程序组成。利用频率上变频方法实现了相对低频磁场的实时测量，同时显示磁场的频率和幅值。因此，实时测量系统能够检测到低至 0.1 nT@1Hz 的微弱交流磁场，有望将 ME 传感器推向实际应用。本文受版权保护。
{"title":"Relatively Low Frequency Magnetic Field Detection System Using Metglas/PZT‐5B Sensor","authors":"Zhihao Jiang, Xiaoxu Liu, Zhejun Jin, Zhao Yao, Yuheng Wang, Shipeng Zhang, Quanming Gao, Shandong Li","doi":"10.1002/pssr.202400133","DOIUrl":"https://doi.org/10.1002/pssr.202400133","url":null,"abstract":"The magnetoelectric (ME) sensor, a new and promising type of magnetic field sensor with ultrahigh sensitivity. However, there are few reports on the research of real‐time measurement system which can promote its practical application. In this study, a novel real‐time measuring approach for weak AC magnetic fields at relatively low frequency was proposed using Metglas/PZT‐5B magnetoelectric sensors. The system mainly consists of an oscilloscope, a signal generator and a program developed with LabVIEW programming. Real‐time measurement of relatively low frequency magnetic fields have been achieved by using frequency up‐conversion methods,simultaneously display the frequency and magnitude of the magnetic field. As a result, the real‐time measurement system was able to detect a weak AC magnetic field as low as 0.1 nT@1Hz, which is promising to push the ME sensor to practical application.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The morphotropic phase boundary (MPB), which arises from the combination of antiferroelectric and ferroelectric phases, demonstrates the highest dielectric constant (κ) compared to other phases. This emphasizes its potential as a leading contender for dielectric films in future DRAM capacitors. MPB‐based high‐κ materials using hafnia have shown a trade‐off between equivalent oxide thickness (EOT) and leakage current density (Jleak) when the crystallization temperature increases with scaling the thickness. In this study, we employed a microwave annealing (MWA) method that can achieve low‐temperature crystallization below 350 °C. The purpose of this method is to mitigate the trade‐off relationships and achieve the strict criteria of current DRAM capacitors. These criteria include low EOT (less than 4 Å) and Jleak (less than 10‐7 A/cm2 at 0.8 V) characteristics. The MWA is capable of relatively low‐temperature annealing by supplying energy to the films through both thermal energy and dipole vibration energy. As a result, we achieved a record low EOT of 3.76 Å and a low leakage current characteristic of 4.2×10‐8 A/cm2 at 0.8 V concurrently. We are confident that our research can be important in addressing the challenges associated with reducing the size of next‐generation DRAM capacitors.This article is protected by copyright. All rights reserved.
由反铁电相和铁电相组合而成的形态相界（MPB）与其他相位相比，具有最高的介电常数（κ）。这凸显了它作为未来 DRAM 电容器介电薄膜主要竞争者的潜力。当结晶温度随着厚度的增加而增加时，使用哈夫尼亚的基于 MPB 的高κ材料显示出等效氧化物厚度（EOT）和漏电流密度（Jleak）之间的权衡。在本研究中，我们采用了一种微波退火 (MWA) 方法，该方法可实现低于 350 °C 的低温结晶。这种方法的目的是缓解权衡关系，实现当前 DRAM 电容器的严格标准。这些标准包括低 EOT（小于 4 Å）和 Jleak（0.8 V 时小于 10-7 A/cm2 ）特性。MWA 能够通过热能和偶极振动能向薄膜提供能量，从而实现相对低温退火。因此，我们同时实现了 3.76 Å 的创纪录低 EOT 和 0.8 V 时 4.2×10-8 A/cm2 的低漏电流特性。我们相信，我们的研究对解决与缩小下一代 DRAM 电容器尺寸相关的挑战具有重要意义。本文受版权保护。
{"title":"Stabilization of Morphotropic Phase Boundary in Hafnia Via Microwave Low‐temperature Crystallization Process for Next‐generation DRAM Technology","authors":"Hunbeom Shin, Giuk Kim, Sujeong Lee, Hyojun Choi, Sangho Lee, Sangmok Lee, Yunseok Nam, Geonhyeong Kang, Hyungjun Kim, Jinho Ahn, Sanghun Jeon","doi":"10.1002/pssr.202400108","DOIUrl":"https://doi.org/10.1002/pssr.202400108","url":null,"abstract":"The morphotropic phase boundary (MPB), which arises from the combination of antiferroelectric and ferroelectric phases, demonstrates the highest dielectric constant (κ) compared to other phases. This emphasizes its potential as a leading contender for dielectric films in future DRAM capacitors. MPB‐based high‐κ materials using hafnia have shown a trade‐off between equivalent oxide thickness (EOT) and leakage current density (Jleak) when the crystallization temperature increases with scaling the thickness. In this study, we employed a microwave annealing (MWA) method that can achieve low‐temperature crystallization below 350 °C. The purpose of this method is to mitigate the trade‐off relationships and achieve the strict criteria of current DRAM capacitors. These criteria include low EOT (less than 4 Å) and Jleak (less than 10‐7 A/cm2 at 0.8 V) characteristics. The MWA is capable of relatively low‐temperature annealing by supplying energy to the films through both thermal energy and dipole vibration energy. As a result, we achieved a record low EOT of 3.76 Å and a low leakage current characteristic of 4.2×10‐8 A/cm2 at 0.8 V concurrently. We are confident that our research can be important in addressing the challenges associated with reducing the size of next‐generation DRAM capacitors.This article is protected by copyright. All rights reserved.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140984307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seong Min Park, Jaegyu Kim, G. Anoop, W. Seol, Su Yong Lee, Hyunjin Joh, Tae Yeon Kim, Jeonyong Choi, Seungbum Hong, Chan‐Ho Yang, Hyeon Jun Lee, J. Jo
Exploring the unique physical properties of oxide perovskites necessitates their growth on diverse single‐crystal substrates. The thin‐film growth of perovskite SrMnO3 (SMO) has been a particular focus of research due to its emerging room‐temperature multiferroicity. Herein, the epitaxial thin films of (110)‐oriented SMO are grown on the piezoelectric (110)‐oriented (1–x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN‐PT) substrate. The effects of the thickness and oxygen annealing on the crystal structure, stoichiometry, and ferroelectric properties of the SMO thin film are systematically investigated. The tensile strain produced by the lattice mismatch between the bulk SMO and the PMN‐PT substrate causes an expansion of the c‐lattice parallel to the in‐plane direction of the substrate. The films show larger a‐, b‐, and c‐lattice parameters than the bulk material, resulting in volume expansion of the unit cell. This lattice expansion is attributed to the generation of oxygen vacancies driven by the reduced formation energy caused by the high elastic strain. Piezoelectric force microscopy reveals that the SMO film contains domains with strain‐mediated in‐plane and vacancy‐mediated out‐of‐plane polarization. Furthermore, the piezoelectric response of the PMN‐PT substrate effectively modulates the biaxial tensile strain in the SMO film, offering a potential strategy for controlling the crystal structure and ferroelectric properties of SMO.
要探索氧化物包晶的独特物理性质，就必须在不同的单晶基底上生长它们。由于包晶 SrMnO3（SMO）具有新兴的室温多铁性，因此其薄膜生长一直是研究的重点。本文在压电（110）取向（1-x）Pb(Mg1/3Nb2/3)O3-xPbTiO3（PMN-PT）基底上生长了取向（110）的 SMO 外延薄膜。系统研究了厚度和氧退火对 SMO 薄膜晶体结构、化学计量学和铁电特性的影响。大块 SMO 和 PMN-PT 衬底之间的晶格失配产生的拉伸应变导致 c-晶格平行于衬底面内方向膨胀。薄膜的 a、b 和 c-晶格参数大于块体材料，导致单位晶胞体积膨胀。这种晶格膨胀可归因于高弹性应变导致的形成能降低所驱动的氧空位的产生。压电显微镜显示，SMO 薄膜包含具有应变介导的面内极化和空位介导的面外极化的畴。此外，PMN-PT 衬底的压电响应可有效调节 SMO 薄膜中的双轴拉伸应变，为控制 SMO 的晶体结构和铁电特性提供了一种潜在的策略。
{"title":"Ferroelectric SrMnO3 Thin Film Grown on (110)‐Oriented PMN‐PT Substrate","authors":"Seong Min Park, Jaegyu Kim, G. Anoop, W. Seol, Su Yong Lee, Hyunjin Joh, Tae Yeon Kim, Jeonyong Choi, Seungbum Hong, Chan‐Ho Yang, Hyeon Jun Lee, J. Jo","doi":"10.1002/pssr.202400025","DOIUrl":"https://doi.org/10.1002/pssr.202400025","url":null,"abstract":"\u0000Exploring the unique physical properties of oxide perovskites necessitates their growth on diverse single‐crystal substrates. The thin‐film growth of perovskite SrMnO3 (SMO) has been a particular focus of research due to its emerging room‐temperature multiferroicity. Herein, the epitaxial thin films of (110)‐oriented SMO are grown on the piezoelectric (110)‐oriented (1–x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN‐PT) substrate. The effects of the thickness and oxygen annealing on the crystal structure, stoichiometry, and ferroelectric properties of the SMO thin film are systematically investigated. The tensile strain produced by the lattice mismatch between the bulk SMO and the PMN‐PT substrate causes an expansion of the c‐lattice parallel to the in‐plane direction of the substrate. The films show larger a‐, b‐, and c‐lattice parameters than the bulk material, resulting in volume expansion of the unit cell. This lattice expansion is attributed to the generation of oxygen vacancies driven by the reduced formation energy caused by the high elastic strain. Piezoelectric force microscopy reveals that the SMO film contains domains with strain‐mediated in‐plane and vacancy‐mediated out‐of‐plane polarization. Furthermore, the piezoelectric response of the PMN‐PT substrate effectively modulates the biaxial tensile strain in the SMO film, offering a potential strategy for controlling the crystal structure and ferroelectric properties of SMO.","PeriodicalId":20059,"journal":{"name":"physica status solidi (RRL) – Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140662261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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