Article
Materials Science, Multidisciplinary
Hongliang Chen, Dongxing Zheng, Yue Wang, Ping Wang, Chao Jin, Zhiqing Li, Haili Bai
Summary: La0.92Sr0.08MnO3 films with varied thickness grown on SrTiO3 substrates by sputtering undergo a secondary metal-insulator transition below a critical temperature when the thickness is equal to or greater than 63 nm. The transition temperature increases gradually with increasing film thickness. Raman spectra analysis shows that the transition is attributed to the reduction of the Jahn-Teller distortion. Further investigations reveal that the transition can occur in different spin structures, and it has potential applications in spintronic devices.
Article
Chemistry, Analytical
Yuting Ye, Chao Chen, Wentao Li, Xingzhou Guo, Haifeng Yang, Haomin Guan, Hua Bai, Wei Liu, Guangcheng Xi
Summary: A rapid and green microwave synthetic route was developed for the preparation of plasmonic W18O49 mesocrystals with no additives. The ultrathin nanowires and oxygen vacancy-rich building units, along with the periodic mesocrystal structure, significantly enhanced the SERS properties, achieving outstanding enhancement factor and ultralow detectable limit. The large-area SERS substrate fabricated showed a low relative standard deviation, indicating good reproducibility.
ANALYTICAL CHEMISTRY
(2021)
Article
Crystallography
Andrey K. Kaveev, Nikolai S. Sokolov, Sergey M. Suturin, Masahiro Sawada, Sergey P. Voskoboynikov
Summary: By choosing appropriate growth conditions and post-growth high temperature annealing, thin epitaxial NiFe2O4 / SrTiO3 films with parameters close to those of bulk nickel ferrite have been successfully fabricated. Spin waves with a low damping parameter and a narrow ferromagnetic resonance line were observed in the annealed samples. Analysis of electron and X-ray diffraction indicated significant improvement in crystalline quality after annealing, and X-ray absorption spectroscopy revealed a completely inverted spinel structure with maximal magnetic moment in the films.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Materials Science, Ceramics
Xu Jiang, Jie Sun, Xiaojie Chai, Yifan Chen, Wei Zhang, Jun Jiang, Anquan Jiang
Summary: The study found that the wall current varies with the angle between the applied electric field and the initial polarization, and that the oxygen vacancy concentration can be controlled through thermal annealing, affecting the magnitude of the domain wall current.
CERAMICS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Wenrui Zhang, Jie Zhang, Shaobo Cheng, Christopher M. Rouleau, Kim Kisslinger, Lihua Zhang, Yimei Zhu, Thomas Z. Ward, Gyula Eres
Summary: Engineering the formation and distribution of oxygen vacancies plays a key role in controlling the evolution of the oxygen sublattice and functional behavior in oxide materials. By incorporating NiO into LSMO films, strong interactions across epitaxial interfaces lead to topotactic phase transitions and morphological evolution in both materials, allowing for systematic tuning of magnetic and electrical properties. The use of self-assembled heterostructure interfaces in the epitaxial nanocomposite platform enables versatile design of topotactic phase structures sensitive to oxygen vacancies.
NANO-MICRO LETTERS
(2022)
Article
Chemistry, Physical
Frederick P. Marlton, Zhaoming Zhang, Yuanpeng Zhang, Thomas E. Proffen, Chris D. Ling, Brendan J. Kennedy
Summary: This study reveals that the local structure of Zr-rich defect-fluorites is different from the previously assumed randomly arranged orthorhombic weberite-type domains. By analyzing data, the relationship between anion sub-lattice disorder and Frenkel defects has been differentiated and quantified. These details directly impact the energy landscape for oxygen migration and are crucial for simulations and design of new materials with improved properties.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Physical
Zhuanglin Weng, Haoliang Huang, Xiaowen Li, Yihao Zhang, Ruiwen Shao, Yazhuo Yi, Yalin Lu, Xierong Zeng, Jizhao Zou, Lang Chen, Wei Li, Yuying Meng, Tewodros Asefa, Chuanwei Huang
Summary: This study demonstrates the highly efficient oxygen evolution reaction (OER) activity of perovskite-derived SrFeO3-delta single-crystal films by selectively tuning the Fe-O coordination structure and film orientation. The optimized structure and properties of the SrFeO2.5 film result in superior electrocatalytic performance, attributed to the peculiar Fe-O coordination framework and ordered oxygen vacancy channels. This delicate tailoring of the SrFeO3-delta films enables tunable catalytic reaction pathways and efficient OER kinetics, with significant implications for the design of cost-effective and high-performance perovskite-based electrocatalysts.
Article
Chemistry, Physical
Zhuanglin Weng, Haoliang Huang, Xiaowen Li, Yihao Zhang, Ruiwen Shao, Yazhuo Yi, Yalin Lu, Xierong Zeng, Jizhao Zou, Lang Chen, Wei Li, Chuanwei Huang, Yuying Meng, Tewodros Asefa
Summary: This study reports a highly efficient oxygen evolution reaction (OER) activity of perovskite-derived SrFeO3-a (0.0 <= a <= 1.0) single-crystal films by selectively tuning the Fe-O coordination structure and film orientation. The oxygen defect channels and peculiar Fe-O coordination framework of SrFeO2.5 film contribute to its superior electrocatalytic performance, and the (111)-oriented BM-SrFeO2.5 films exhibit even better OER performance due to their low adsorption free energy and small charge transfer resistance.
Article
Materials Science, Multidisciplinary
Lei Cao, Andreas Herklotz, Diana Rata, Chenyang Yin, Oleg Petracic, Ulrich Kentsch, Manfred Helm, Shengqiang Zhou
Summary: The efficient control of vacancy profiles in epitaxial La0.7Sr0.3MnO3-delta thin films through helium implantation leads to significant changes in physical properties, transitioning from ferromagnetic metallic to antiferromagnetic insulating, with a substantial increase in resistivity by four orders of magnitude at room temperature. This result offers an attractive means for tuning the emergent physical properties of oxide thin films through a strong coupling between strain, defects, and valence.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Matthew Barone, Chaojie Du, Luka Radosavljevic, Don Werder, Xiaoqing Pan, Darrell G. Schlom
Summary: Researchers reported the epitaxial synthesis of a 2D SnO van der Waals crystal with layers aligned perpendicular to the surface. Although useful devices cannot be fabricated due to the nanowire morphology, this discovery is significant in the fields of 2D materials synthesis and p-type oxides.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Multidisciplinary
Gene Yang, So Yeun Kim, Changhee Sohn, Jong K. Keum, Dongkyu Lee
Summary: This study focuses on the influence of heterointerfaces between Ruddlesden-Popper (RP) phases and ABO(3) perovskites on the kinetics of oxygen electrocatalysis at elevated temperatures. The research shows that partial decorations of LNO on LSCO thin films significantly increase the oxygen surface exchange coefficients (k(chem)), while full LNO coverage leads to a reduction in these coefficients. The enhanced oxygen surface exchange kinetics of LSCO films are attributed to the increased oxygen vacancies by creating the heterointerface between LSCO and LNO.
APPLIED SCIENCES-BASEL
(2021)
Review
Chemistry, Multidisciplinary
Martin Klein, Siegfried R. Waldvogel
Summary: This article reviews the importance of the corresponding counter reaction in electro-organic synthesis and discusses how selecting appropriate counter reactions can improve the performance and selectivity of electrolytic conversion.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Jun Cao, Haijian Huang, Yifan Qu, Weijian Tang, Zeheng Yang, Weixin Zhang
Summary: This study investigates the interfacial engineering of Li-rich cathode materials using a lithiated phosphate coating layer, which effectively improves the electrochemical performances of Li-rich cathode materials.
Article
Chemistry, Multidisciplinary
Philipp Gribisch, Andreas Fissel
Summary: The structural and morphological properties of gadolinium oxide (Gd2O3) grown at high temperatures with molecular beam epitaxy on Si(001) were investigated for different stages of growth. The results suggest that the nanowire-like structures on Si(001) substrates have specific orientations, and the density and length can be tuned by changing the oxygen partial pressure.
Review
Chemistry, Physical
Tribani Boruah, Rebecca L. Melen, Thomas Wirth
Summary: This article highlights a novel synthetic pathway for reducing phosphine oxides to phosphines through thermodynamic and mechanistic investigation, without the need for stoichiometric activators.
Article
Chemistry, Multidisciplinary
Kyle P. Kelley, Anna N. Morozovska, Eugene A. Eliseev, Vinit Sharma, Dundar E. Yilmaz, Adri C. T. van Duin, Panchapakesan Ganesh, Albina Borisevich, Stephen Jesse, Peter Maksymovych, Nina Balke, Sergei Kalinin, Rama K. Vasudevan
Summary: This study reports the first observation of enhanced electromechanical response in BaTiO3 thin films through dynamic local oxygen vacancy control. It demonstrates that piezoelectricity can persist past the bulk Curie temperature and that an internal electric field further enhances the intrinsic electrostriction. The findings highlight the pivotal role that dynamics of vacancies in complex oxides play in determining functional properties and suggest a new route towards achieving enhanced ferroic response in ferroelectrics and other ferroic materials with higher functional temperature windows.
ADVANCED MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Saurabh Srivastava, Kenneth E. Lee, Eugene A. Fitzgerald, Stephen J. Pennycook, Silvija Gradecak
Summary: This study develops a new type of freestanding quantum dot-based color converter for efficient optical down-conversion. By controlling quantum dot thickness and pixel size, high resolution displays with small pixel sizes can be achieved. The technology can be used for QD-based RGB displays with ultrahigh resolution.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Multidisciplinary
G. J. Omar, W. L. Kong, H. Jani, M. S. Li, J. Zhou, Z. S. Lim, S. Prakash, S. W. Zeng, S. Hooda, T. Venkatesan, Y. P. Feng, S. J. Pennycook, L. Shen, A. Ariando
Summary: We have successfully controlled the Rashba spin-orbit interaction by tuning the asymmetric hybridization between Ti orbitals at the LaAlO3/SrTiO3 interface. This was achieved by introducing a LaFeO3 layer, which altered the lattice polarization and trapped charge carriers, resulting in a large Rashba effect at the interface without external bias. Our findings, verified through experimental and computational methods, open new avenues for controlling Rashba interaction and designing next-generation spin orbitronics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Yong Yu, Xiao Xu, Yan Wang, Baohai Jia, Shan Huang, Xiaobin Qiang, Bin Zhu, Peijian Lin, Binbin Jiang, Shixuan Liu, Xia Qi, Kefan Pan, Di Wu, Haizhou Lu, Michel Bosman, Stephen J. Pennycook, Lin Xie, Jiaqing He
Summary: The authors find that the quantum gaps in GeTe-based materials can decouple carrier and phonon transport, leading to high thermoelectric performance. By selectively scattering phonons while allowing carriers to pass effectively, the quantum gaps provide a general method for boosting the thermoelectric performance of other materials.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Roger Guzman, Shoucong Ning, Ruizi Zhang, Hongtao Liu, Yinhang Ma, Yu-Yang Zhang, Lihong Bao, Haitao Yang, Shiduan Du, Michel Bosman, Stephen J. Pennycook, Hong-Jun Gao, Wu Zhou
Summary: In this study, the local atomic structure and magnetic behavior of V-rich V1+xTe2 nanoplates with embedded V3Te4 nanoclusters have been investigated. The self-intercalated V3Te4 magnetic phase, which possesses a distorted 1T'-like monoclinic structure, is locally stabilized by V intercalations. The phase transition is controlled by the electron doping from the intercalant V ions. The results provide insights into the studies of dilute magnetism at the 2D limit and strategies for the manipulation of magnetism for spintronic applications.
Article
Geochemistry & Geophysics
Ge Bian, Olga Ageeva, Vladimir Roddatis, Chen Li, Timothy J. Pennycook, Gerlinde Habler, Rainer Abart
Summary: Needle-shaped, lath-shaped, and plate-shaped magnetite micro-inclusions in plagioclase from mafic intrusive rocks were studied using optical microscopy and scanning transmission electron microscopy. The orientation and crystallographic relationships between the magnetite micro-inclusions and the plagioclase were found to be controlled by lattice match along the interfaces. Recrystallization of magnetite was observed, which could potentially affect the natural remanent magnetization of magnetite-bearing plagioclase grains.
JOURNAL OF PETROLOGY
(2023)
Article
Multidisciplinary Sciences
Qiangbing Guo, Xiao-Zhuo Qi, Lishu Zhang, Meng Gao, Sanlue Hu, Wenju Zhou, Wenjie Zang, Xiaoxu Zhao, Junyong Wang, Bingmin Yan, Mingquan Xu, Yun-Kun Wu, Goki Eda, Zewen Xiao, Shengyuan A. Yang, Huiyang Gou, Yuan Ping Feng, Guang-Can Guo, Wu Zhou, Xi-Feng Ren, Cheng-Wei Qiu, Stephen J. Pennycook, Andrew T. S. Wee
Summary: A van der Waals crystal, niobium oxide dichloride (NbOCl2), has been found to exhibit weakened interlayer electronic coupling and monolayer-like excitonic behavior in the bulk form. It also has a scalable second-harmonic generation intensity that is three orders higher than that in monolayer WS2. Additionally, the strong second-order nonlinearity in thin flakes as thin as 46 nm enables correlated parametric photon pair generation through a spontaneous parametric down-conversion (SPDC) process. This is the first SPDC source demonstrated in two-dimensional layered materials and the thinnest SPDC source ever reported. This research opens avenues for developing van der Waals material-based ultracompact on-chip SPDC sources and high-performance photon modulators in both classical and quantum optical technologies.
Article
Chemistry, Multidisciplinary
Mengsha Li, Pingfan Chen, Yingli Zhang, Yuan Zhang, Zhenghao Liu, Chunhua Tang, Jing Yang Chung, Mingqiang Gu, Junxue Li, Zhen Huang, Gan Moog Chow, Changjian Li, Stephen J. Pennycook
Summary: Nanocomposite films show promise for multifunctional devices by integrating different functionalities within a single film. The microstructure of the precipitate/secondary phase plays a crucial role in determining the properties of composites. However, there has been limited study on quantitatively characterizing the interphase strain between different phases. In this study, a PbTiO3(PTO)/PbO composite system was prepared in nano-spherical and nanocolumnar configurations. The nanocolumnar structure exhibited a much larger and more uniform strained region in PTO, resulting in enhanced ferroelectric properties.
Article
Chemistry, Physical
Mingquan Xu, De-Liang Bao, Aowen Li, Meng Gao, Dongqian Meng, Ang Li, Shixuan Du, Gang Su, Stephen J. Pennycook, Sokrates T. Pantelides, Wu Zhou
Summary: By improving the stability and sensitivity of the instrument, we have successfully observed the specific vibrational signals between substitutional impurities and neighboring carbon atoms in monolayer graphene. This work allows for the direct observation of local phonon modes with chemical-bonding sensitivity, providing more insights into defect-induced physics in graphene.
Article
Materials Science, Multidisciplinary
Tengfei Cao, Guodong Ren, Ding -Fu Shao, Evgeny Y. Tsymbal, Rohan Mishra
Summary: The recent observation of ferroelectricity in binary metal oxides, such as HfO2, ZrO2, Hf0.5Zr0.5O2, and Ga2O3, has attracted much attention. Hole doping is proposed to play a key role in stabilizing polar phases in these oxides. First-principles calculations demonstrate that holes mainly occupy one of the oxygen sublattices and their localization enhances the electrostatic energy of the system, making the polar phase more stable at high concentrations. The electrostatic mechanism is responsible for the stabilization of the ferroelectric phase in HfO2 doped with elements that introduce holes to the system.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Hongyan Mei, Guodong Ren, Boyang Zhao, Jad Salman, Gwan Yeong Jung, Huandong Chen, Shantanu Singh, Arashdeep S. Thind, John Cavin, Jordan A. Hachtel, Miaofang Chi, Shanyuan Niu, Graham Joe, Chenghao Wan, Nick Settineri, Simon J. Teat, Bryan C. Chakoumakos, Jayakanth Ravichandran, Rohan Mishra, Mikhail A. Kats
Summary: This work demonstrates that a bulk crystal with subtle periodic modulations in its structure, Sr9/8TiS3, exhibits transparent and positive-uniaxial properties in the mid- to far-infrared range, with extraordinary index n(e) = 4.5 and ordinary index n(o) = 2.4. The unique structural modulations contribute to the formation of highly oriented electron clouds, resulting in record birefringence.
ADVANCED MATERIALS
(2023)
Article
Geosciences, Multidisciplinary
Rajan K. Chakrabarty, Nishit J. Shetty, Arashdeep S. Thind, Payton Beeler, Benjamin J. Sumlin, Chenchong Zhang, Pai Liu, Juan C. Idrobo, Kouji Adachi, Nicholas L. Wagner, Joshua P. Schwarz, Adam Ahern, Arthur J. Sedlacek, Andrew Lambe, Conner Daube, Ming Lyu, Chao Liu, Scott Herndon, Timothy B. Onasch, Rohan Mishra
Summary: Observations of smoke plumes in the United States shows that atmospheric short-wave absorption due to wildfire smoke is mainly caused by dark brown carbon particles. Wildfires release large amounts of black carbon and light-absorbing organic carbon, known as brown carbon, into the atmosphere, which disrupts Earth's radiation budget. It is important to quantify these radiative impacts as wildfires are predicted to increase globally.
Article
Multidisciplinary Sciences
Xin Li, Yu Yun, Arashdeep Singh Thind, Yuewei Yin, Qiang Li, Wenbin Wang, Alpha T. N'Diaye, Corbyn Mellinger, Xuanyuan Jiang, Rohan Mishra, Xiaoshan Xu
Summary: This study investigates the electrical modulation of magnetic states in single-phase multiferroic materials using domain-wall magnetoelectric (ME) coupling. Results show that the domain-wall ME effect is dramatically enhanced when the separation between ferroelectric (FE) domain walls shrinks below the characteristic width of the antiferromagnetic (AFM) domain walls. These findings suggest that the domain-wall ME effect is capable of electrical control of magnetization.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
Sungyoon Jung, Tengfei Cao, Rohan Mishra, Pratim Biswas
Summary: This study investigates the effect of CO2 concentration in the feed stream on CH4 oxidation in oxy-combustion systems. Experimental results show that an increase in CO2 concentration leads to a higher rate of CO2 generation and complete CH4 oxidation. Theoretical calculations suggest that a high surface coverage of CO2 on Pd reduces the activation energy for CH4 dissociation and subsequent oxidation reactions. These findings indicate the beneficial role of a CO2-rich environment in reducing oxygen content in exhaust gases.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Review
Multidisciplinary Sciences
Sergei V. Kalinin, Colin Ophus, Paul M. Voyles, Rolf Erni, Demie Kepaptsoglou, Vincenzo Grillo, Andrew R. Lupini, Mark P. Oxley, Eric Schwenker, Maria K. Y. Chan, Joanne Etheridge, Xiang Li, Grace G. D. Han, Maxim Ziatdinov, Naoya Shibata, Stephen J. Pennycook
Summary: This article discusses the combination of STEM technology with machine learning methods, explores STEM imaging methods and data quantification, and their application opportunities in the study of complex materials' chemistry and physics. The article also mentions the infrastructure requirements for the broad application of ML methods and discusses the potential application of ML in experiment automation and novel scanning modes.
NATURE REVIEWS METHODS PRIMERS
(2022)
