Article
Physics, Applied
Yushui Tian, Yulu Zhou, Miao Zhao, Yifang Ouyang, Xiaoma Tao
Summary: The effect of VB metal doping HfO2 and a metal co-doping method based on electronic compensation to regulate oxygen defects and improve ferroelectricity in HfO2-based ferroelectric thin films are studied. The results show that co-doping with Sc-Nb and Sc-Ta is an effective method to enhance ferroelectricity in HfO2.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Jian Shi, Chunying Chao, Yingying Gao, Hao Li, Suxiang Ge, Caixia Li, Xi Chen, Weiwei He
Summary: Designing an architecture that introduces oxygen vacancies (OVs) in ferroelectric materials without weakening the ferroelectric polarization has a positive effect on separating and inhibiting recombination of photogenerated carriers. This study reported an indirect strategy to form PTO@BiOCl-OVs heterojunction nanoplates by introducing BiOCl rich in OVs into the positive surface of ferroelectrics via a simple hydrothermal method and UV light irradiation. The 3% PTO@BiOCl-OVs heterojunction nanoplates showed excellent photocatalytic activity for RhB degradation under visible light. ESR signals confirmed the presence of reactive species such as O-2(-), center dot OH, and O-1(2).
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Zhaohui Ren, Luoyuan Ruan, Lichang Yin, Karthik Akkiraju, Livia Giordano, Zhongran Liu, Shi Li, Zixing Ye, Songda Li, Hangsheng Yang, Yong Wang, He Tian, Gang Liu, Yang Shao-Horn, Gaorong Han
Summary: It is reported that surface oxygen vacancies can be confined electrostatically near the perimeter interface between Pt {111} nanocrystals and the negative polar surface (001) of ferroelectric PbTiO3. This catalyst demonstrates tunable catalytic CO oxidation kinetics by increasing the O-2 gas pressure, opening a new pathway for CO oxidation catalytic activity.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yoon Jung Lee, Kootak Hong, Kyeongho Na, Jiwoong Yang, Tae Hyung Lee, Byungsoo Kim, Chung Wung Bark, Jae Young Kim, Sung Hyuk Park, Sanghan Lee, Ho Won Jang
Summary: By controlling phase transitions in correlated materials, new functional properties can be achieved. This study demonstrates the control of a nonvolatile metal-insulator transition in vanadium dioxide (VO2) using a ferroelectric layer, showing enhanced coupling between correlated electrons and ferroelectric polarization. The research provides insights into interface properties, structural phase transitions, and design principles for heteroepitaxial correlated materials.
ADVANCED MATERIALS
(2022)
Article
Physics, Applied
Yi-Jan Lin, Chih-Yu Teng, Chenming Hu, Chun-Jung Su, Yuan-Chieh Tseng
Summary: This paper proposes an approach to enhance Hf0.5Zr0.5O2 (HZO) ferroelectric orthorhombic phase formation through in situ NH3 plasma treatment. The treatment suppresses interfacial diffusion between HZO and the top TiN electrode, reducing oxygen vacancies within HZO. The results demonstrate improved reliability and ferroelectric performance of HZO devices with stable transfer characteristics and memory windows after NH3 treatment.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Yongfei Cui, Peng Guo, Peipei Dang, Huanhuan Sun, Panpan Jing, Xiaoma Tao
Summary: By introducing Fe3+ doping strategy, oxygen vacancies were induced and ferroelectric polarization in Bi3TiNbO9 nanosheets was enhanced, leading to band structure modulation and charge carrier kinetics steering. Experimental results confirmed that Fe not only reduced bandgaps but also improved electron-hole separation, promoting carrier transport and increasing carrier density.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Xu Li, Chengbiao Yang, Yuanzheng Xia, Xinlong Zeng, Peng Shen, Linglong Li, Feiya Xu, Duanjun Cai, Yaping Wu, Zhiming Wu, Shuping Li, Junyong Kang
Summary: This study demonstrates nonvolatile electrical tuning of valley excitons in monolayer and bilayer WS2 using a ferroelectric gating approach, which enhances the room-temperature valley polarization through control of interfacial charge trapping/detrapping and other effects. This work reveals effective electrical control over valley excitons in semiconductors, providing a promising strategy for the development of valleytronics devices.
Article
Materials Science, Multidisciplinary
Andong Xiao, Yao Liu, Tianzi Yang, Wentao Jia, Xin Song, Yu Qian, Chenyu Liang, Tianyu Ma
Summary: This article reports a topotactic phase transition from perovskite to oxygen vacancies ordered brownmillerite structure in transition metal oxides. The oxygen vacancies formation process in (101)-Nd0.5Sr0.5MnO3-delta films was observed by TEM during in-situ high vacuum annealing. The results show a vertical brownmillerite structure with oxygen vacancies channel perpendicular to the film plane. Additionally, the associated physical properties of the topotactic phases can be controlled by the phase transition, leading to a distinct magnetic phase.
Article
Chemistry, Multidisciplinary
Hyeon Han, Arpit Sharma, Holger L. Meyerheim, Jiho Yoon, Hakan Deniz, Kun-Rok Jeon, Ankit K. Sharma, Katayoon Mohseni, Charles Guillemard, Manuel Valvidares, Pierluigi Gargiani, Stuart S. P. Parkin
Summary: Oxygen defects and their atomic arrangements play a significant role in the physical properties of transition metal oxides. This study demonstrates a method to electrically control the ordering of oxygen vacancy channels using ionic liquid gating, providing a new approach for the fabrication of oxitronic devices.
Article
Materials Science, Ceramics
Zhikai Yan, Depeng Li, Xin Zhang, Qiaoqiao Men, Bingbing Fan, Li Guan, Xiaoqin Guo, Rui Zhang, Biao Zhao
Summary: In this study, dual-phase high entropy oxide ceramics were prepared using a simple sintering process, and the crystal structure, microstructure, elemental chemical state, magnetic property and microwave absorption properties were studied. The results show that controlling the content of spinel phase and sintering temperature can improve the magnetic property and microwave absorption capability of the materials.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Bhaskar Chandra Khan, Prabir K. Mukherjee
Summary: In this study, the isotropic to smectic-A phase transition in taper-shaped liquid crystal was described using Landau theory. Experimental observations showed electro-optical switching and a polarization peak similar to ferroelectric behavior in the smectic phase of taper-shaped liquid crystal. Phenomenological theory was used to explain this behavior, and the switched polarization behavior with respect to temperature, electric field, and frequency was described for both isotropic and smectic-A phases. Additionally, the temperature dependence of the switching time was discussed, showing qualitative agreement between theoretical and experimental results.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Optics
Esther Nabadda, Noureddine Bennis, Michal Czerwinski, Aleksandra Walewska, Leszek R. Jaroszewicz, Maria del Mar Sanchez-Lopez, Ignacio Moreno
Summary: In this work, a ferroelectric liquid crystal (FLC) modulator with a large switching rotation angle close to 90 degrees is fabricated and characterized. The modulator acts as a switchable wave-plate with an in-plane rotation of the principal axis under bipolar voltage. The device behaves as a binary pi phase modulator independently of the input state of polarization in the ideal situation of half-wave retardance. Physico-chemical properties of the liquid crystalline mixture used to fabricate the FLC modulator with such a large switching angle are provided. The device optical properties are characterized, and the polarization-independent pi phase shift is demonstrated using an adapted Young's type interferometer.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Prabir K. Mukherjee
Summary: The properties of ferroelectric liquid crystals are studied under pressure using Landau theory. Results show that the transition temperature, helical pitch, spontaneous polarization, and tilt angle increase with pressure, while the dielectric permittivity decreases. Theoretical and experimental results show good qualitative agreement.
Article
Physics, Applied
Min Zhou, Xinyang Lu, Zewen Wu, Yiqun Xie, Yanxia Xing, Yin Wang
Summary: In this study, the electron transport properties of the LaNiO3/BaTiO3/LaNiO3 FTJ with a low concentration of OVs were investigated using NECPA-DFT, revealing that OVs play a critical role in determining the electron transport properties of an FTJ. The tunnel electroresistance ratio monotonously increases with the OVs concentration, reaching 5898% for a 9% OVs concentration.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Subhash Sharma, J. M. Siqueiros, Oscar Raymond Herrera
Summary: This study investigates the effect of Er doping on the properties of BiFeO3 nanoparticles, showing improvements in dielectric, electrical, and optical properties. The Er-doped BFO exhibits enhanced dielectric properties, better P-E loops, and potential applications in the visible spectrum, making it a promising candidate for memory device applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Qin Wan, Fei Zeng, Yiming Sun, Tongjin Chen, Junwei Yu, Huaqiang Wu, Zhen Zhao, Jiangli Cao, Feng Pan
Summary: This study demonstrates a memristive system with adaptive nucleation of phase-change nanoclusters, which responds to stimulation strength and exhibits action potential firing. The reversible nucleation of phase-change nanoclusters is confirmed by high-resolution transmission electron microscopy. This compact memristive system plays an important role in neuromorphic computing.
Article
Multidisciplinary Sciences
Wenxuan Zhu, Cheng Song, Qian Wang, Hua Bai, Siqi Yin, Feng Pan
Summary: A novel van der Waals ferromagnet PtTe2Ge1/3 with high air stability and above room-temperature Curie temperature has been synthesized through a displacement reaction in Pt/Cr2Ge2Te6 heterostructure. This work demonstrates the unique anti-metal-activity-order reaction tendency in 2D transition-metal magnets and advances progress towards practical 2D spintronics.
NATIONAL SCIENCE REVIEW
(2023)
Article
Nanoscience & Nanotechnology
Qian Wang, Youdi Gu, Chong Chen, Leilei Qiao, Feng Pan, Cheng Song
Summary: In this study, researchers discovered that classical transition-metal oxide (TMO) brownmillerite SrCoO2.5 films can transition to a metastable perovskite phase in a weak acidic solution. This metastable perovskite exhibits strong ferromagnetism and greatly elevated electrical conductivity, similar to prototypical perovskite SrCoO3. Two possible mechanisms were proposed to explain this phenomenon, with the control experiments indicating that the dominant process is active oxygen filling.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Xin Wu, Danpeng Gao, Xianglang Sun, Shoufeng Zhang, Qi Wang, Bo Li, Zhen Li, Minchao Qin, Xiaofen Jiang, Chunlei Zhang, Zhuo Li, Xinhui Lu, Nan Li, Shuang Xiao, Xiaoyan Zhong, Shangfeng Yang, Zhong'an Li, Zonglong Zhu
Summary: In this study, a simple design strategy of polymer hole-transporting materials (HTMs) is reported, which can modulate the wettability and promote the anchoring by introducing pyridine units into the polyarylamine backbone, resulting in efficient and stable inverted perovskite solar cells (PVSCs).
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ping-Luen Ho, Zhihao Huang, Lei Jin, Si-Young Choi, Rafal E. Dunin-Borkowski, Joachim Mayer, Shik Chi Edman Tsang, Xiaoyan Zhong
Summary: Aberration-corrected analytical transmission electron microscopy (TEM) is used to determine the atomic-scale cation order in a nanosized Sr3Fe2ReO9 phase, revealing tripled-layered repeats of Fe and Re cations along [111](pc) and an ordering vector of 1/3[111]*. Density functional theory calculations based on a relaxed theoretical model consistent with the experimental images determine the magnetic ground states and exchange parameters of the newly discovered Sr3Fe2ReO9 phase, where nearest-neighbour Fe and Re cations are coupled antiferromagnetically.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Yizhe Liu, Xintong Li, Shoufeng Zhang, Zilong Wang, Qi Wang, Yonghe He, Wei-Hsiang Huang, Qidi Sun, Xiaoyan Zhong, Jue Hu, Xuyun Guo, Qing Lin, Zhuo Li, Ye Zhu, Chu-Chen Chueh, Chi-Liang Chen, Zhengtao Xu, Zonglong Zhu
Summary: A molecularly engineered MOF system based on mercaptan-metal links has been designed, demonstrating excellent electroconductivity and efficient electrocatalytic oxygen evolution reaction (OER) performance.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Peisen Liu, Sulei Fu, Rongxuan Su, Huiping Xu, Boyuan Xiao, Cheng Song, Fei Zeng, Feng Pan
Summary: This paper reports a longitudinal leaky surface acoustic wave (LLSAW) mode acoustic resonator with a large electromechanical coupling factor, high operating frequency, and efficient spurious suppression. It systematically investigates the design spaces such as supporting substrate, propagation angle, and lithium niobate (LN) thickness, and demonstrates a high-performance LLSAW resonator with a large kt(2) without interference from other spurious modes. The fabricated LLSAW resonators exhibit a near spurious-free response with an operating frequency over 6 GHz and a kt(2) as large as 22.7%.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Rongxuan Su, Sulei Fu, Junyao Shen, Zengtian Lu, Huiping Xu, Rui Wang, Cheng Song, Fei Zeng, Weibiao Wang, Feng Pan
Summary: In this study, a 32-degree Y-X LiNbO3/SiO2/Si heterostructure with high electro-mechanical coupling coefficient was constructed to develop a SAW filter with excellent RF performance for 5G NR. The fabricated filter exhibited a large bandwidth, low insertion loss, and flat passband, demonstrating the potential for commercial implementation of SAW filters in 5G NR.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Materials Science, Multidisciplinary
S. Shuang, G. J. Lyu, D. Chung, X. Z. Wang, X. Gao, H. H. Mao, W. P. Li, Q. F. He, B. S. Guo, X. Y. Zhong, Y. J. Wang, Y. Yang
Summary: In this study, we developed a series of medium-entropy alloys (MEAs) with high strength, superior fracture toughness, and ultra-high corrosion resistance. Interestingly, our MEAs exhibit an unusual anti-corrosion behavior as their corrosion resistance increases with increasing acidity. This behavior can be attributed to the surface chemical complexity of our MEAs, which facilitates the formation of metastable medium entropy passive films.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Huiping Xu, Sulei Fu, Rongxuan Su, Peisen Liu, Rui Wang, Fei Zeng, Cheng Song, Weibiao Wang, Feng Pan
Summary: In response to the demand for highly integrated and miniaturized radio frequency front-end (RFFE) modules, multi-passband filters that support multi-channel compounding have become the focus. This study proposes a new design of a dual-passband surface acoustic wave (SAW) filter based on a 32 degrees YX-LiNbO3 (LN)/SiO2/SiC multilayered structure. The filter is of a standalone ladder topology and consists of dual-mode resonators that simultaneously excite the shear horizontal (SH) mode and high-order SH mode through electrode thickness modulation. The fabricated dual-band filter shows compact layout and diminished area occupancy, making it a promising solution for high-performance dual-passband SAW filter for sub-6 GHz RF application.
Article
Materials Science, Multidisciplinary
Xiang Chen, Wei Tian, Yu He, Hongrui Zhang, Tyler L. Werner, Saul Lapidus, Jacob P. C. Ruff, Ramamoorthy Ramesh, Robert J. Birgeneau
Summary: The structural and magnetic properties of F5GT single crystals with minimal Fe deficiency were investigated using x-ray and neutron scattering techniques. It was found that the crystals undergo an irreversible, first-order transition at T_S≈110K upon first cooling, leading to a conversion of stacking order from ABC to AA. Importantly, the magnetic properties, including the direction of magnetic moment and the enhanced T_C after thermal cycling, are closely related to the change in stacking order. This work highlights the significant influence of lattice symmetry on the magnetism in F5GT.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Quantum Science & Technology
Qin Wan, Fei Zeng, Junwei Yu, Tongjin Chen, Ziao Lu, Feng Pan
Summary: Research and development of memristor-based neuromorphic networks has reached large-scale application stage, but a thorough understanding of the adopted memristors is still lacking. In this study, a method to manipulate the local activity of NbO quantum dot (QD) system by creating an electrode tip is proposed, enabling reversible nucleation behavior and periodic pulsing. These mechanisms contribute to the information-energy conversion in the QD system and provide a more precise and low energy-consumption approach for neuromorphic computing.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Yicong Ma, Lin Yang, Xiangchen Hu, Miao Zhang, Geping Qu, Xiaopeng Bai, Haifeng Sun, Feng Zhu, Xiaoyan Zhong, Xiao Chen, Zongxiang Xu, Yi Yu, Zhifeng Huang
Summary: Structural chirality is introduced into nano-alloys to enhance their properties. Layer-by-layer glancing angle deposition is used to synthesize chiral nanoparticles with multiple elements at a low substrate temperature, leading to the amplification of chiroplasmonic optical activities. This approach has the potential to be applied in asymmetric catalysis for the synthesis of enantiomers with specific chirality.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Shixuan Liang, Lei Han, Yunfeng You, Hua Bai, Feng Pan, Cheng Song
Summary: Out-of-plane spin polarization (crz), generated by triangular spin configuration in non-collinear antiferromagnets, including IrMn3, has potential applications for magnetic memory. Our study demonstrates that the interface between IrMn3 and permalloy also contributes to the generation of crz, and interfacial crz can be eliminated by inserting Cu. We propose that the interface-relevant crz is independent of exchange coupling and suggest possible origins. These findings enrich the understanding of crz in antiferromagnet/ferromagnet bilayers and propose a potential path for optimizing low-power magnetic memories.
Article
Chemistry, Multidisciplinary
Hongrui Zhang, Xiang Chen, Tianye Wang, Xiaoxi Huang, Xianzhe Chen, Yu-Tsun Shao, Fanhao Meng, Peter Meisenheimer, Alpha N'Diaye, Christoph Klewe, Padraic Shafer, Hao Pan, Yanli Jia, Michael F. Crommie, Lane W. Martin, Jie Yao, Ziqiang Qiu, David A. Muller, Robert J. Birgeneau, Ramamoorthy Ramesh
Summary: This study reports the experimental observation of spin-orbit torque magnetization self-switching at room temperature in a layered polar ferromagnetic metal, Fe2.5Co2.5GeTe2, providing a direct pathway towards applicable 2D spintronic devices.
ADVANCED MATERIALS
(2023)
