Article
Physics, Applied
V Govinden, Q. Zhang, D. Sando, N. Valanoor
Summary: The study reveals that tuning the thickness of the PbZr0.4Ti0.6O3 layer in the ferroelectric heterostructures can affect the depolarization field, leading to changes in domain morphology and coercive voltage. This is attributed to both strain-induced tetragonality increase and depolarization field-induced changes in domain morphology.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Kangli Xu, Tianyu Wang, Yongkai Liu, Jiajie Yu, Zhenhai Li, Jialin Meng, Hao Zhu, Qingqing Sun, David Wei Zhang, Lin Chen
Summary: Hafnium lanthanum oxide (HLO) thin films, known for their excellent ferroelectric properties, have been identified as a promising strategy for future non-volatile memory applications. In this study, the impact of Zr doping on the ferroelectric behavior and endurance of HLO thin films was systematically investigated for the first time. The results showed that controlled Zr incorporation led to significant enhancement in ferroelectric, dielectric, and endurance performance.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Yu Zhang, Lijuan Huang, Chung Ming Leung, Wei Zhang, Zhixin Xu, Jiaxing Xie, Wuming Xue, Xiao Wu, Chunlin Zhao, Tengfei Lin, Cong Lin, Min Gao
Summary: The electric-field-modulation (E-modulation) of photoluminescence (PL) properties in rare-earth Er3+-doped Pb0.96La0.04Zr0.9Ti0.1O3 (PLZT) antiferroelectrics (AFEs) has been investigated. The AFE phase stability of PLZT doped with various Er contents and their E-modulated PL properties have been systematically studied. The ceramics exhibit both upconversion and downconversion PL effects and show excellent E-dependent dual-mode PL tunability, demonstrating the potential for optoelectronic applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Inorganic & Nuclear
Yushui Tian, Yulu Zhou, Miao Zhao, Yifang Ouyang, Xiaoma Tao
Summary: The effect of Ce doping on the structure and oxygen defects of ferroelectric HfO2 was studied, and the optimal doping concentration for the formation of ferroelectric phase was determined. The mechanism of Ce doping and its role in promoting the formation of oxygen vacancies in HfO2 were also investigated.
JOURNAL OF SOLID STATE CHEMISTRY
(2023)
Article
Chemistry, Physical
Luyong Zhang, Guo Tian, Wenda Yang, Dongfeng Zheng, Chuanjie Lin, Jianbiao Xian, Yihang Guo, Xingchen Zhang, Xiuqin Qiu, Lanping Zhang, Zhen Fan, Deyang Chen, Zhipeng Hou, Minghui Qin, Jun-Ming Liu, Xingsen Gao
Summary: The precise patterning of nanoscopic domain structures in as-grown epitaxial PbTiO3 films can be achieved by introducing an ultrathin pre-patterned doping layer. This doping layer can effectively reverse the interfacial built-in bias, allowing for the transfer of the nano-patterns into the ferroelectric film's domain structure.
JOURNAL OF MATERIOMICS
(2023)
Article
Chemistry, Physical
Hansung Kim, Gunwu Ju, Seung-Hwan Kim, Kiyoung Lee, Myoungho Jeong, Hyun Cheol Koo, Hyung-jun Kim
Summary: The study utilized interdiffusion between epitaxial Ge layers and GaAs substrates to control the doping concentration and type of the Ge layers, achieving extremely high n-type doping concentration in a Ge layer grown at low temperature. Subsequent annealing processes led to a decrease in doping concentration and an n- to p-type transition due to differences in diffusivity between As and Ga atoms.
SURFACES AND INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Zhongwen Li, Hui Shen, Graham Dawson, Zhengzhong Zhang, Yanzong Wang, Feng Nan, Guang Song, Guannan Li, Yangjiang Wu, Hao Liu
Summary: In this study, the authors used vector piezoresponse force microscopy to observe spontaneous ferroelectric topological domains in ferroelectric materials and discovered their topological arrangements and reversible switching characteristics. They also found that the domain diameter changes with pulse duration in different intrinsic domain structures and confirmed the stability of these topological domain states in the atmosphere.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Tingfeng Song, Romain Bachelet, Guillaume Saint-Girons, Ignasi Fina, Florencio Sanchez
Summary: By using an ultrathin seed layer, high-quality epitaxial films of orthorhombic Hf0.5Zr0.5O2 can be obtained at a lower temperature, and they exhibit enhanced endurance.
Article
Chemistry, Applied
Jafar Hussain Shah, Anum Shahid Malik, Ahmed Mahmoud Idris, Saadia Rasheed, Hongxian Han, Can Li
Summary: In this study, particulate BFO and Mn-doped BiFeO3 were synthesized by the sol-gel method, demonstrating that Mn doping significantly enhances the oxygen evolution reaction (OER) activity under visible light irradiation. The bandgap of Mn-doped BFO could be reduced by varying the Mn doping amount, leading to improved absorption of visible light and decreased activation energy for water oxidation. Density functional theory (DFT) calculations suggested that surface Fe species are the active sites for water oxidation, with Mn doping leading to the lowest over-potential measured in this study. The synergistic effect of bandgap narrowing in Mn-doped BFO increases the photocatalytic water oxidation activity by inhibiting charge recombination and reducing activation energy.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Materials Science, Ceramics
Anna Zofia Szeremeta, Jan Macutkevic, Maciej Zubko, Seweryn Miga, Sarunas Svirskas, Irena Gruszka, Janusz Koperski, Juras Banys, Andrzej Molak
Summary: We report on the influence of Sr, Cr, Mn, and Mg doping ions on the structural and dielectric properties of barium calcium titanate (BCT) ceramics over a wide temperature and frequency range. Our findings reveal phase transitions from paraelectric to ferroelectric phases, distinguish diffused phase transition features induced by Cr and Mn ions, and highlight relaxor-like features caused by Mg ion doping. Additionally, the doping of Cr, Mn, and Mg ions affects the relaxation times of the B-sublattice ions jumping. Low-temperature ferroelectric-ferroelectric phase transitions were confirmed through dielectric and pyroelectric measurements, demonstrating the induction of non-zero net polarization by an applied electric field.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Yoonho Ahn, Jong Yeog Son
Summary: The conduction properties of ferroelectric domains formed in nanoscale BiFeO3 (BFO) dots were evaluated for non-volatile memory applications. Different sizes of BFO dots were fabricated on Nb-doped SrTiO3 substrates, and the domain wall current and polarization-dependent current were measured. Multiple ferroelectric domains were found within one BFO dot, and a large current was observed at the domain wall location. The electrical resistance state depended on the presence or absence of domain walls.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Arun Kumar, Raimondo Cecchini, Lorenzo Locatelli, Claudia Wiemer, Christian Martella, Lucia Nasi, Laura Lazzarini, Roberto Mantovan, Massimo Longo
Summary: This study achieved the optimized large-area growth of Bi2Te3 epitaxial layers on unbuffered i-Si(111) substrates via MOVPE and identified the key factors for maximizing layer quality. The grown Bi2Te3 thin layers exhibit high crystal quality, stoichiometry, uniformity, and topological insulator properties, showing potential for technology transfer to innovative devices.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Arne J. Klomp, Ruben Khachaturyan, Theophilus Wallis, Karsten Albe, Anna Gruenebohm
Summary: This study investigates the stability of domain walls in ferroelectric material BaTiO3 using molecular dynamic simulations, and finds that microscopic thermal fluctuations play a crucial role in domain wall dynamics and stability. When domain walls are small enough, thermal fluctuations can cause the walls to come into contact and annihilate each other, thus limiting the maximum achievable domain wall density in nanoelectronic devices.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Hyun Wook Song, Jong Yeog Son
Summary: We studied the physical properties of Cr-doped epitaxial BiFeO3 films and how they are affected by ferro-electric domain structures. The crystallinity of the films changed based on the Cr concentration, with some films exhibiting mixed crystallinity. The ferroelectric polarization increased up to a certain Cr concentration, but decreased afterwards due to the formation of certain crystalline structures. Increasing the Cr concentration had a positive effect on the piezoelectric, leakage current, and ferromagnetic properties of the films. The ferroelectric domain structures also changed with increasing Cr concentration.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Engineering, Electrical & Electronic
Andra-Georgia Boni, Cristina Chirila, Lucian Trupina, Cristian Radu, Lucian Dragos Filip, Valeriu Moldoveanu, Ioana Pintilie, Lucian Pintilie
Summary: Comprehensive studies to obtain true ferroelectric p-n junctions by controlled doping are missing. Recently, it has been shown that ferroelectric films doped with Nb or Fe have different orientations of polarization. P-n homojunctions were built and their properties in relation to ferroelectric polarization were studied.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Z. Wang, O. Muransky, H. Zhu, T. Wei, Z. Zhang, M. Ionescu, C. Yang, J. Davis, G. Hu, P. Munroe, W. Windes
Summary: The ion irradiation-induced microstructural changes in a carbon-fibre reinforced carbon-matrix (C/C) composite were investigated using Raman spectroscopy. It was found that the high concentration of pre-existing crystal lattice defects in the C/C composite had a significant impact on the disordering of the crystal lattice. In contrast, graphite with fewer pre-existing defects behaved in a more predictable manner. The results suggest the importance of eliminating crystal lattice defects in the as-manufactured microstructure of C/C composites for radiation-tolerant applications. Additionally, the study identified a knowledge gap regarding the electronic energy loss effect on ion irradiation damage in carbon-based materials at intermediate ion energies.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Chunxi Hao, Yu Wang, Teng Lu, Felipe Kremer, Ray Withers, Chang Liu, Aqun Zheng, Sen Yang, Xiaoping Song, Xiaobing Ren, Yun Liu
Summary: Large magnetostriction with low saturation magnetic field is observed in Fe-Pd ferromagnetic strain glass alloys, which is highly desirable for miniaturized sensor and actuator applications. The high performance magnetostriction is found to originate from the structure of ferromagnetic strain glass, which consists of local chemical order forming tetragonal martensitic nanodomains with local crystal symmetry breaking. The combination of martensitic nanodomains and low modulus is necessary to achieve both large magnetostriction and a low saturation field.
Article
Physics, Applied
Yosuke Isoda, Daisuke Kan, Takuya Majima, Yuichi Shimakawa
Summary: We investigated the electrochemical responses of (100), (110), and (111)-oriented oxygen-deficient perovskite SrFeO2.5+y epitaxial films. Only the (100)-oriented films exhibited changes associated with gate-voltage-induced electrochemical reductions. The electrochemically reduced (100) films were found to accommodate protons, forming the proton-containing oxide H0.11SrFeO2.5+y. Our results suggest that oxygen vacancies preferentially form along the {100} axes and ion diffusion in electrochemical reactions predominantly occurs along the {100} directions in SrFeO2.5+y.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Physical
Minming Jiang, Jiang Xu, Paul Munroe, Zong-Han Xie
Summary: In this study, the hydrogen storage mechanism on the CuNi co-doped MgH2(101) surface was investigated using the first-principles approach. The results showed that the most stable adsorption site for hydrogen on the surface is above the Ni atom, and there is substantial charge exchange between the hydrogen molecule and Ni atom.
Article
Engineering, Environmental
Yang Wang, Stephen Joseph, Xiang Wang, Zhe H. Weng, David R. G. Mitchell, Mitchell Nancarrow, Sarasadat Taherymoosavi, Paul Munroe, Guitong Li, Qimei Lin, Qing Chen, Markus Flury, Annette Cowie, Olivier Husson, Lukas Van Zwieten, Yakov Kuzyakov, Johannes Lehmann, Baoguo Li, Jianying Shang
Summary: Biochar amendments increased total soil carbon by 71%, 182%, and 210% for B30, B60, and B90, respectively. The application of biochar at different rates significantly increased the subsoil inorganic carbon (SIC), mainly occurring in the subsoil below 1 m. The study provided critical knowledge on the impact of biochar application on carbon stocks in subsoil in the long term.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Ashok Meghwal, Samuel Pinches, Ameey Anupam, Lionel Lie, Paul Munroe, Christopher C. Berndt, Andrew Siao Ming Ang
Summary: In this study, a near-dense and crack-free CoCrFeNi medium entropy alloy (MEA) coating was fabricated using extreme-high-speed laser material deposition (EHLA). The coating retained a single-phase face-centered cubic (FCC) structure, and showed anisotropic mechanical deformation behavior at a localized level. Microstructure-mechanical property correlations confirmed the homogeneous mechanical properties of the coating at the bulk level.
Article
Chemistry, Physical
Yanjia Zhang, Miho Sawamura, Maho Harada, Yusuke Noda, Masanobu Nakayama, Masato Goto, Daisuke Kan, Yuichi Shimakawa, Benoit Denis Louis Campeon, Daisuke Shibata, Toshiaki Ohta, Naoaki Yabuuchi
Summary: This study investigates the Li3NbO4-CoO binary system and finds that although Li4/3Co2/9Nb4/9O2 exhibits a reversible capacity increase as electrode material, there are irreversible structural changes in its electrochemical cycles, leading to the instability of anionic redox.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Taro Kamada, Taisei Ueda, Shuta Fukuura, Takashi Yumura, Saburo Hosokawa, Tsunehiro Tanaka, Daisuke Kan, Yuichi Shimakawa
Summary: In this study, catalytic model systems based on Pd-loaded SrFeOx films were fabricated to investigate the phenomenon of hydrogen spillover. The results showed that hydrogen spillover on the SrFeOx support can extend over long distances, up to 600 μm. The reduction of Fe4+ on the support surface induced by hydrogen spillover yields large energies, driving the unexpectedly long-distance hydrogen diffusion. These findings provide a deeper understanding of hydrogen spillover and offer insights for designing catalyst systems with enhanced properties.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Nanoscience & Nanotechnology
Ashok Meghwal, Surinder Singh, Soumya Sridar, Wei Xiong, Colin Hall, Paul Munroe, Christopher C. Berndt, Andrew Siao Ming Ang
Summary: A novel high entropy alloy-medium entropy alloy composite coating was designed using a CALPHAD approach, which showed potential for industrial applications. The experimental results demonstrated that the composite coating had higher hardness and superior wear resistance, making it promising for structural applications.
SCRIPTA MATERIALIA
(2023)
Correction
Materials Science, Multidisciplinary
Chunxi Hao, Yu Wang, Teng Lu, Felipe Kremer, Ray Withers, Chang Liu, Aqun Zheng, Sen Yang, Xiaoping Song, Xiaobing Ren, Yun Liu
Article
Chemistry, Multidisciplinary
Hideki Narita, Jun Ishizuka, Daisuke Kan, Yuichi Shimakawa, Youichi Yanase, Teruo Ono
Summary: The superconducting diode effect (SDE) has great potential for developing ultralow power consumption circuits and non-volatile memory. However, controlling the SDE requires precise tuning of current, temperature, magnetic field, or magnetism. This study demonstrates a zero-field SDE with an efficiency of up to 40% in Fe/Pt-inserted non-centrosymmetric Nb/V/Ta superconducting artificial superlattices. The polarity and magnitude of the zero-field SDE are controllable by magnetization direction, indicating the influence of the effective exchange field on Cooper pairs.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Yanjia Zhang, Miho Sawamura, Maho Harada, Yusuke Noda, Masanobu Nakayama, Masato Goto, Daisuke Kan, Yuichi Shimakawa, Benoit Denis Louis Campeon, Daisuke Shibata, Toshiaki Ohta, Naoaki Yabuuchi
Summary: In this study, Li3NbO4-CoO binary system was investigated as electrode materials for lithium storage applications. It was found that with the increase of Li3NbO4 fraction, cation-disordered rocksalt structure formed in Li-excess phases, leading to the degradation of performance. Factors affecting the reversibility and irreversibility of anionic redox were further discussed through systematic study of the binary system of Li3NbO4-CoO.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Engineering, Electrical & Electronic
Ryunosuke Takahashi, Takuo Ohkochi, Daisuke Kan, Yuichi Shimakawa, Hiroki Wadati
Summary: Using a magneto-optical Kerr effect (MOKE) microscope, we observed laser-induced magnetization switching in ferrimagnetic oxide NiCo2O4 (NCO) epitaxial thin films with perpendicular magnetic anisotropy. Laser pulses at 1030 nm were used to irradiate the NCO thin film at different temperatures (300-400 K) while altering the parameters of pulse interval, fluence, and the number of pulses in the absence of an external magnetic field. We observed accumulative all-optical helicity-dependent switching above 380 K. Our observation of oxide NCO thin films facilitates magnetization switching using ultrafast lasers without the need for a magnetic field.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yufan Shen, Mitsutaka Haruta, I. -Ching Lin, Lingling Xie, Daisuke Kan, Yuichi Shimakawa
Summary: The binary fluorite oxide Hf0.5Zr0.5O2 has attracted significant attention due to its distinct and superior ferroelectricity. However, stabilizing its metastable phase and understanding the growth mechanism remain challenging. Recent investigations have shown the growth of metastable ferroelectric Hf0.5Zr0.5O2 on structurally dissimilar perovskite oxides, which are nonpolar in their bulk form. Yet, the growth mechanism of these unique fluorite-perovskite heterostructures is still not fully explored.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Electrochemistry
Lingling Xie, Yosuke Isoda, Takuya Majima, Yufan Shen, Daisuke Kan, Yuichi Shimakawa
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
(2023)
