Article
Materials Science, Multidisciplinary
Weon Cheol Lim, Jitendra Pal Singh, Younghak Kim, Jonghan Song, Keun Hwa Chae, Tae-Yeon Seong
Summary: The study shows that thermal annealing significantly affects the properties of zinc oxide thin films, including relaxation of stress, variation in optical band-gap, and occurrence of vacancies and defects. These changes are revealed through X-ray techniques, providing a better understanding of the performance changes in zinc oxide films.
Article
Chemistry, Physical
Yujun Zhang, Jiahui Chen, Keisuke Ikeda, Kohei Yamagami, Yue Wang, Yongseong Choi, Akira Yasui, Jing Ma, Yuanhua Lin, Cewen Nan, Hiroki Wadati
Summary: In this study, the magnetism and electronic structure changes across the AFM-FM transition of Ni-doped FeRh epitaxial thin films were investigated using XMCD and HAXPES techniques. The results showed that the remnant FM phase at low temperature possesses a smaller Rh moment than the normal FM phase, while an increase of Rh 4d density of state at the Fermi level and a possible well-screened Ni 2p state were found in the FM phase. In addition, the FM fluctuation of the inter-site Fe-Fe exchange coupling within the AFM phase was observed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Multidisciplinary
Xiaoran Liu, Shiang Fang, Yixing Fu, Wenbo Ge, Mikhail Kareev, Jong-Woo Kim, Yongseong Choi, Evguenia Karapetrova, Qinghua Zhang, Lin Gu, Eun-Sang Choi, Fangdi Wen, Justin H. Wilson, Gilberto Fabbris, Philip J. Ryan, John W. Freeland, Daniel Haskel, Weida Wu, J. H. Pixley, Jak Chakhalian
Summary: The discovery of signatures for the long-sought magnetic Weyl semimetallic phase in high-quality epitaxial thin films of (111)-oriented Eu2Ir2O7 has been reported. An intrinsic anomalous Hall effect was observed with colossal coercivity but vanishing net magnetization, emerging right below the onset of a peculiar magnetic phase with all-in-all-out antiferromagnetic ordering. The experimental anomalous Hall conductivity is consistent with the theoretical prediction, likely arising from nonzero Berry curvature emanated by Weyl node pairs near the Fermi level activated by broken cubic crystal symmetry at the top and bottom terminations of the thin film.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Alan Farhan, Federico Stramaglia, Maria Cocconcelli, Nikolai Kuznetsov, Lide Yao, Armin Kleibert, Cinthia Piamonteze, Sebastiaan van Dijken
Summary: In this study, we investigated the structural and magnetic properties of Tb(Fe0.2Mn0.2Co0.2Cr0.2Ni0.2)O-3 (T5BO) high-entropy oxide perovskite thin films. By using synchrotron-based x-ray absorption spectroscopy and x-ray magnetic circular dichroism, we performed an element-sensitive study on epitaxial T5BO thin films. The results revealed a magnetic multiphase with variable ferromagnetic ordering, which provides a promising approach for designing ferroic properties in Tb-based HEOP thin films.
Article
Multidisciplinary Sciences
Fridtjof Kielgast, Ivan Baev, Torben Beeck, Federico Pressacco, Michael Martins
Summary: Investigated the electronic and magnetic properties of mass-selected V and Fe monomers, as well as the heterodimer Fe1V1, deposited on a Cu(001) surface using X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Found weak adatom-substrate-coupling for both elements, determined the ground state symmetries of the adatoms using group theoretical arguments, and observed a switching of magnetic moments from antiparallel to parallel orientation in the dimer due to the existence of a noncollinear spin-flop phase.
SCIENTIFIC REPORTS
(2021)
Article
Nanoscience & Nanotechnology
Gyanendra Panchal, Anjali Panchwanee, Manish Kumar, Katharina Fritsch, Ram Janay Choudhary, Deodutta Moreshwar Phase
Summary: By controlling the number of laser shots from two constituent phase targets in pulsed laser deposition film growth, the microstructures in vertically aligned nanocomposite thin films can be effectively tuned, leading to significantly enhanced magnetoresistance and modulated in-plane exchange bias. Additionally, a unique perpendicular exchange bias effect is observed in these heterostructures, showcasing an enhanced perpendicular exchange bias field.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Zhi Zhang, Er Liu, Xianyang Lu, Wen Zhang, Yurong You, Guizhou Xu, Zhan Xu, Ping Kwan Johnny Wong, Yichuan Wang, Bo Liu, Xiaojiang Yu, Jing Wu, Yongbing Xu, Andrew Thye Shen Wee, Feng Xu
Summary: This study demonstrates the optical manipulation of magnetism in Co2FeSi films grown on a flexible polyimide substrate, showing that strain engineering can modify the magneto-optical interaction and trigger the excitation of spin wave modes. In addition, Gilbert damping and spin-orbit coupling in Co2FeSi can be significantly tuned by altering the applied strain, suggesting a promising way to manipulate spin wave propagation. These results advance the field of optical manipulation of magnetism into spin wave dynamics and open up new possibilities for applying strain engineering in spin orbitronics and magnonics devices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Hiroo Tajiri, Loku Singgappulige Rosantha Kumara, Yuya Sakuraba, Zixi Chen, Jian Wang, Weinan Zhou, Kushwaha Varun, Kenji Ueda, Shinya Yamada, Kohei Hamaya, Kazuhiro Hono
Summary: Inverse Heusler alloy Mn2CoAl thin films, known as spin-gapless semiconductors (SGS), were grown by three different methods and their properties were investigated. Although all the samples exhibited SGS characteristics, none of them formed the expected structure.
Article
Multidisciplinary Sciences
Shinya Ota, Pham Van Thach, Hiroyuki Awano, Akira Ando, Kentaro Toyoki, Yoshinori Kotani, Tetsuya Nakamura, Tomohiro Koyama, Daichi Chiba
Summary: The study reveals that the compensation temperature of ferrimagnetic Tb-Fe films on a flexible substrate is significantly affected by tensile strain, resulting in a reduction of magnetic moments of both Fe and Tb. Analyzed using molecular field theory, the changes in exchange coupling between Fe and Tb atoms are speculated to be the cause of this phenomenon.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Multidisciplinary
Julia Lumetzberger, Verena Ney, Anna Zakharova, Nieli Daffe, Daniel Primetzhofer, F. Wilhelm, A. Rogalev, Andreas Ney
Summary: Zinc ferrite (ZnFe2O4) epitaxial thin films were grown on MgAl2O4 and Al2O3 substrates using reactive magnetron sputtering. The study investigated the structural and magnetic properties of the films, confirming epitaxial growth of ZnFe2O4 with nominal stoichiometric composition and long-range magnetic order. The growth rate of the films was found to be the main parameter influencing the temperature Tf, while growth temperature or Ar:O2 ratio did not have a systematic effect on Tf. The highest Tf, indicating magnetic glassiness, was observed in ZnFe2O4 epitaxial films.
Article
Physics, Applied
Tomohiro Yasuda, Kenta Amemiya, Takashi Suemasu
Summary: In this study, we successfully fabricated ultrathin Mn4N films with a thickness of around 4 nm and discovered a reversed sign of the anomalous Hall resistivity as the film thickness decreased. X-ray magnetic circular dichroism measurements revealed that the magnetic structure of Mn4N with a thickness of around 4 nm is different from that of conventional ferrimagnetic Mn4N films. These findings are of great importance for studying spin-orbit torque and interfacial Dzyaloshinskii-Moriya interaction in Mn4N ultrathin films.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Kelly M. Walsh, Kimo Pressler, Matthew J. Crane, Daniel R. Gamelin
Summary: This study investigates the magneto-optical responses of CsEuCl3 perovskite material in the near-UV/visible region using magneto-photoluminescence and magnetic circular dichroism spectroscopies. The results reveal that CsEuCl3 perovskite exhibits complete spin alignment and ferromagnetism at low temperatures, as well as spin-polarized photoluminescence in the presence of a magnetic field.
Article
Materials Science, Multidisciplinary
Kenta Amemiya, Kaoruho Sakata
Summary: This study uses the depth-resolved x-ray magnetic circular dichroism (XMCD) technique to determine the anisotropy of magnetic moments at the interface of a Co thin film sandwiched by Au layers. The results show that the perpendicular orbital magnetic moment is significantly larger than the in-plane orbital magnetic moment at the interface, while the inner Co layers exhibit an opposite tendency.
Article
Materials Science, Multidisciplinary
Sanjeev Gautam, Pardeep K. Thakur, Shalendra Kumar, Ranber Singh, Di-Jing Huang, Younghak Kim, Keun Hwa Chae
Summary: The experimental results indicate that the ZnCO3 phase after carbon implantation is structurally non-distortive with orbital anisotropy, supported by XLD experiment. Additionally, the absence of XMCD signal at O K- and C K-edges further confirms that bulk VSM ferromagnetism is not related to the magnetic polarization of O 2p/C 2p orbitals.
Article
Chemistry, Physical
E. Annese, A. Ali, J. Barreto, G. Felix, F. Stavale
Summary: This study aims to investigate the relationship between oxide thin-film surface plane and its electronic properties, revealing the sensitivity of 3d orbital occupancy and their intensity ratio to surface orientation, and quantifying the variation of relative 3d occupation as a function of strain using XLD sum rules. These results provide important insights for identifying and further engineering well-defined crystallographic surfaces in various fields of applications.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Brandon Wilfong, Vaibhav Sharma, Jared Naphy, Omar Bishop, Steven P. Bennett, Joseph Prestigiacomo, Radhika Barua, Michelle E. Jamer
Summary: The study investigated the effects of post-synthesis annealing temperature on Fe3Ga4 samples, revealing a trend in ISDW-FM transition temperature with changes in unit cell volume. External pressure and crystallographic changes were found to influence the transition temperatures, highlighting the importance of understanding the mechanism and nature of the intermediate ISDW phase for future device applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Multidisciplinary Sciences
Samuel L. Zelinka, Grant T. Kirker, George E. Sterbinsky, Keith J. Bourne
Summary: This study used XANES to investigate the changes in copper oxidation states in wood treated with different wood preservatives and found that in nearly all cases the copper oxidation state was Cu++. The results confirmed previous beliefs about copper oxidation states in wood and provided further insights into the corrosion mechanism of metals embedded in treated wood.
Article
Multidisciplinary Sciences
Shanlin Li, Ruguang Ma, Jingcong Hu, Zichuang Li, Lijia Liu, Xunlu Wang, Yue Lu, George E. Sterbinsky, Shuhu Liu, Lei Zheng, Jie Liu, Danmin Liu, Jiacheng Wang
Summary: To achieve a zero-carbon economy, advanced anode catalysts are needed for hydrogen production and biomass upgrading using renewable energy. This study focuses on the electrochemical oxidation of nickel-metalloids to create oxyanion-coordinated amorphous nickel oxyhydroxides. The results show that substitution with phosphorus enhances the electrooxidation activity of methanol.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
S-K Bac, K. Koller, F. Lux, J. Wang, L. Riney, K. Borisiak, W. Powers, M. Zhukovskyi, T. Orlova, M. Dobrowolska, J. K. Furdyna, N. R. Dilley, L. P. Rokhinson, Y. Mokrousov, R. J. McQueeney, O. Heinonen, X. Liu, B. A. Assaf
Summary: In this work, the researchers experimentally demonstrate the topological anomalous Hall effect (AHE) in MnBi2Te4, which is sensitive to the perpendicular magnetic moment and its canting angle. By synthesizing a large-area quasi-3D MnBi2Te4 using molecular beam epitaxy, they observe the evolution of AHE under different magnetic fields, which exhibits an antiferromagnetic response and a super-linear relationship. Their findings reveal the topological anomalous Hall response in non-collinear ferromagnetic and antiferromagnetic phases.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Physical
Brandon Wilfong, Adrian Fedorko, Danil R. Baigutlin, Olga N. Miroshkina, Xiuquan Zhou, Gregory M. Stephen, Adam L. Friedman, Vaibhav Sharma, Omar Bishop, Radhika Barua, Steven P. Bennett, Duck Young Chung, Mercouri G. Kanatzidis, Vasiliy D. Buchelnikov, Vladimir V. Sokolovskiy, Bernardo Barbiellini, Arun Bansil, Don Heiman, Michelle E. Jamer
Summary: In this study, a complex magnetic phase diagram of metallic Fe3Ga4 at room temperature was obtained, and a model for the intermediate antiferromagnetic helical spin structure state was proposed. The results showed that the antiferromagnetic state had a helically ordered spiral propagating along the c-axis, with the magnetic moments rotating in the ab-plane. Under applied magnetic field, the antiferromagnetic state exhibited a transition to conical ordering, before entering a completely field-polarized ferromagnetic state.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Instruments & Instrumentation
Valeria Lauter, Kang Wang, Tim Mewes, Artur Glavic, Boris Toperverg, Mahshid Ahmadi, Badih Assaf, Bin Hu, Mingda Li, Xinyu Liu, Yaohua Liu, Jagadeesh Moodera, Leonid Rokhinson, Deepak Singh, Nian Sun
Summary: M-STAR is a next generation polarized neutron reflectometer with advanced capabilities for nanoscience and spintronics studies. It enables improved grazing incidence diffraction measurements and opens new possibilities for probing near-surface dynamics.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Chemistry, Multidisciplinary
Nirjhar Bhattacharjee, Krishnamurthy Mahalingam, Alexandria Will-Cole, Yuyi Wei, Adrian Fedorko, Cynthia T. Bowers, Michael Page, Michael McConney, Don Heiman, Nian Xiang Sun
Summary: In this study, a novel method of low-temperature growth of magnetic insulators on topological insulators (TIs) is demonstrated by interface engineering. A thin titanium capping layer followed by oxidation in atmosphere is used to protect the TI surface, while still maintaining spin transport and strong interfacial magnetic exchange-interaction. This provides a new approach for the growth of magnetic insulators on TIs.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Sujan Budhathoki, Arjun Sapkota, Ka Ming Law, Smriti Ranjit, Gregory M. Stephen, Don Heiman, Michelle E. Jamer, Tim Mewes, Adam J. Hauser
Summary: This study reports the magnetic and magnetodynamic properties of strained epitaxial FeGe thin films on Ge(111) substrates, highlighting the generation of orbital moment in tensile-strained FeGe and the impact of in-plane tensile strain on magnetic transition temperature. X-ray magnetic circular dichroism shows partially quenched atomic orbitals in the films, indicating potential utility of strained FeGe in spintronic applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Brandon Wilfong, Vaibhav Sharma, Omar Bishop, Adrian Fedorko, Don Heiman, Radhika Barua, Michelle E. Jamer
Summary: The magnetic order of Fe3Ga4 can be effectively tuned by vanadium doping, leading to changes in crystal structure and magnetic properties.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Zachary D. Hood, Anil U. Mane, Aditya Sundar, Sanja Tepavcevic, Peter Zapol, Udochukwu D. Eze, Shiba P. Adhikari, Eungje Lee, George E. Sterbinsky, Jeffrey W. Elam, Justin G. Connell
Summary: Sulfide-based solid-state electrolytes (SSEs) have high ionic conductivity and favorable mechanical properties, making them promising for next-generation solid-state batteries. Thin Al2O3 coatings grown on Li6PS5Cl powders using atomic layer deposition simultaneously address the stability issues and improve cell performance. These coated powders exhibit higher ionic conductivities, lower electronic conductivities, and improved stability at the Li-SSE interface, leading to significantly improved battery cycle life.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Khagesh Kumar, Sasawat Jamnuch, Leily Majidi, Saurabh Misal, Alireza Ahmadiparidari, Michael A. Dato, George E. Sterbinsky, Tianpin Wu, Amin Salehi-Khojin, Tod A. Pascal, Jordi Cabana
Summary: In this study, researchers investigated the electronic structure changes of MoS2 nanosheets during the carbon dioxide reduction reaction (CO2RR) through experimental and computational methods. They discovered the existence of Mo-CO2 binding in the active state, which perturbs the hybridized Mo 4d-S 3p states and is influenced by electrochemically induced sulfur vacancies. These findings provide insights into the excellent performance of MoS2 in CO2RR and could be used as a screening criterion for improving the activity and selectivity of transition-metal dichalcogenides (TMDCs) in general.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Marcos Lucero, Davis B. Armitage, Xin Yang, Sean K. Sandstrom, Mason Lyons, Ryan C. Davis, George E. Sterbinsky, Namhyung Kim, David M. Reed, Xiulei Ji, Xiaolin Li, Zhenxing Feng
Summary: In this study, Prussian blue electrodes were cycled in a water-in-salt electrolyte, revealing the advantages of aqueous Na-ion batteries. The Fe2.4+ to Fe3+ redox reaction of the electrodes showed excellent cycling stability, with over 18,000 cycles and more than 90% capacity retention at the 10C rate. Systematic characterizations confirmed the phase transition and iron oxidation state evolution, providing insights into the high rate and long durability of the cathode material.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jacob Jeskey, Yong Ding, Yidan Chen, Zachary D. Hood, George E. Sterbinsky, Mietek Jaroniec, Younan Xia
Summary: This study presents a facile method to produce atomically isolated metal atoms with high loadings in uniform carbon nanospheres. The catalytic activity and selectivity of the obtained single-atom catalysts (SACs) can be controlled by changing the transition metal used.
Article
Materials Science, Multidisciplinary
Jiashu Wang, Xinyu Liu, Tianyi Wang, Mykhaylo Ozerov, Badih A. Assaf
Summary: Topological crystalline insulators from the Pb1-xSnxSe family exhibit textbook Dirac surface states that are nearly electron-hole symmetric and isotropic in momentum space. The high mobility of charge carriers in these materials allows for reaching the quantum limit at reasonably achievable magnetic fields. By combining magnetooptical Landau level spectroscopy, Shubnikov-de Haas transport measurements, and consistent modeling, we accurately determine the band parameters and g factor of the topological states in this system. Our findings reveal an enhanced and field-dependent g factor compared to bulk states, providing crucial information for the realization and understanding of novel quantized Hall effect originating from the mirror-protected valley-degenerate Dirac states in this material family.
Article
Chemistry, Multidisciplinary
Jiashu Wang, William Powers, Zhan Zhang, Michael Smith, Bradlee J. McIntosh, Seul Ki Bac, Logan Riney, Maksym Zhukovskyi, Tatyana Orlova, Leonid P. Rokhinson, Yi-Ting Hsu, Xinyu Liu, Badih A. Assaf
Summary: Research on strained Sn1-xInxTe thin films grown in the (111) plane reveals the potential hosting of Majorana zero modes and the existence of quantum interference effects and superconducting fluctuations in conductivity. The study also shows a crossover from weak antilocalization to localization in superconducting samples, indicating that superconductivity may mainly originate from charge carriers in strongly spin-orbit split trivial states. The observed significant increase in conductivity above T-c suggests the presence of superconducting fluctuations in the material.
