Article
Chemistry, Physical
Guillermo Lopez-Polin, Hugo Aramberri, Jorge Marques-Marchan, Benjamin Weintrub, Kirill Bolotin, Jorge Cerda, Agustina Asenjo
Summary: Research has focused on increasing the ANE coefficient of materials, but little effort has been devoted to increasing the power supplied by the effect. By fabricating micrometer-sized devices and using materials with high ANE thermopower, record power densities generated by the ANE have been achieved.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Mengchao Li, Huali Yang, Yali Xie, Kai Huang, Lili Pan, Wei Tang, Xilai Bao, Yumeng Yang, Jie Sun, Xinming Wang, Shenglei Che, Run-Wei Li
Summary: The magnetic properties of flexible magnetic films are sensitive to mechanical stress due to magnetoelastic coupling, which affects the performance of flexible magnetoelectronic devices. We demonstrate that stacking different materials in multilayers can enhance the stress stability of the magnetic properties. The strength of magnetoelastic anisotropy and the initial effective magnetic anisotropy play significant roles in determining the stress stability of the film.
Article
Chemistry, Physical
Young Chan Won, Sang Ho Lim
Summary: The study investigates the perpendicular magnetic anisotropy and crystalline structure of Ta/NiFeB/MgO stacks. Annealing induces PMA and increases magnetic moment, with the thinnest 0.5-nm Ta layer showing the strongest PMA at 400 degrees Celsius. X-ray diffraction confirms the formation of NiFe (001) phase essential for high tunneling magnetoresistance ratio.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Multidisciplinary Sciences
Y. Hsiao, D. B. Gopman, K. Mohanchandra, P. Shirazi, C. S. Lynch
Summary: Uniform magnetic behavior within arrays of magnetoelectric heterostructures is crucial for strain-mediated microdevices. However, nonuniform magnetization reversal occurs due to various factors including surface roughness, strain non-uniformity, and fabrication-induced imperfections. In this study, Co/Ni microdisks were grown on PMN-30PT and Si substrates, and the out-of-plane magnetization reversal was characterized. The results showed that the coercivity variation across the microdisks was observed on both substrates, and the surface roughness effect led to relatively larger coercivity on PMN-30PT.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Young Chan Won, Sang Ho Lim
Summary: The magnetic and interface properties of [Pt/Co/Pt] were studied, revealing different magnetic properties of the Co layer parts and the influence of the top Pt layer on the magnetic properties of the Co layer. Magnetometry was demonstrated as an effective tool for understanding the interface quality of magnetic multilayer systems.
SCIENTIFIC REPORTS
(2021)
Article
Nanoscience & Nanotechnology
Chloe S. Taylor, Marzieh Savadkoohi, Pawan Tyagi, Jenae E. Shoup, Dario A. Arena, Julie A. Borchers, James Eckert, Daniel B. Gopman
Summary: This study examines the role of sputter damage in limiting the perpendicular magnetic anisotropy and interlayer exchange coupling in Pt/Co/Ir-based synthetic antiferromagnets. By changing the process gas, the energy of backscattered sputter gas ions can be reduced, leading to an enhancement in the perpendicular magnetic anisotropy and interlayer exchange coupling energy.
ACS APPLIED NANO MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Kun-Jen Hsueh, Po-Chun Chang, Li-Jie Liaw, Alltrin Dhanarajagopal, Minn-Tsong Lin, Wen-Chin Lin
Summary: In this study, a hydrogen-sensitive FePd alloy film was deposited on Co/[Pt/Co]4/Pt multilayers with perpendicular magnetic anisotropy (PMA). The spin-reorientation transition (SRT) from perpendicular to in-plane direction was observed in the 2-nm-thick FePd capped multilayer through hydrogenation. Magneto-optic Kerr effect measurements were performed in hydrogen gas at different pressures. Reversible SRT was demonstrated with the cyclic change of H2 pressure. Furthermore, tuning the strength of the PMA multilayer changed the SRT-critical thickness of the FePd cap and the hydrogen-induced SRT behavior, which has potential applications in spintronics.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Min He, Tiankuo Xu, Yang Gao, Chaoqun Hu, Jianwang Cai, Ying Zhang
Summary: This research demonstrates the generation of mixed-type skyrmions in symmetric Pt/Co(1.55)/Pt multilayers at room temperature, showing reversible evolution dependent on magnetic field. The high D value in this structure allows for the creation of skyrmions, with Neel-type skyrmions transforming into Bloch-type as D decreases. The non-uniform D at interfaces may play a role in generating mixed-type skyrmions.
Article
Engineering, Electrical & Electronic
Clemens Muehlenhoff, Michal Krupinski, Arkadiusz Zarzycki, Manfred Albrecht
Summary: In this study, the magnetotransport properties of Co/Pt based perpendicular synthetic antiferromagnetic (p-SAF) structures with Ru interlayers were investigated. The number of Co/Pt multilayer (ML) stacks and Ru interlayers in the p-SAF structures were varied to examine changes in their magnetoresistive effects. The alignment of magnetization directions of the MLs in the ML/Ru/ML stacks of the p-SAF generated a giant magnetoresistance effect (GMR), while the anisotropic magnetoresistance effect (AMR) at each ML further influenced the resistance of the system. The study results have important implications for understanding and application of magnetoresistive effects.
IEEE SENSORS JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Danian A. Dugato, Jeovani Brandao, Fanny Beron, Ricardo B. da Silva, Samuel Flewett, David A. Shapiro, Julio C. Cezar, Lucio S. Dorneles, Thiago J. A. Mori
Summary: Magnetic multilayers with heavy metal/ferromagnetic interfaces are essential for data storage and spintronics. In this study, Pt/Co/Pt multilayers grown by magnetron sputtering are used to demonstrate the stabilization of isolated skyrmion bubbles at zero magnetic field. The interface disorder and asymmetry resulting from thinning the Co layer lead to nonzero interfacial Dzyaloshinskii-Moriya interaction (iDMI) and Pt proximity induced moment (PIM), affecting the magnetic properties of the multilayers. The interplay between PIM and iDMI is crucial for the nucleation of skyrmion bubbles and highlights the importance of controlling interface phenomena for future applications.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Xi Chen, Shao-Long Jiang, Dong-Wei Wang, Kang Yang, Jin-Hui Lu, Guang-Hua Yu
Summary: The effect of ultrathin Fe layer on perpendicular magnetic anisotropy (PMA) in Co/Pt multilayers was investigated. The position of the Fe layer at the interface strongly influenced the PMA. When the Fe layer was doped at the Co/Pt interface, the PMA decreased monotonically with increasing Fe layer thickness. However, when the Fe layer was doped at the Pt/Co interface, the PMA showed a peak at a specific thickness. The variation in PMA is mainly attributed to the tuning of electron occupation states at Fe-doped Pt/Co interface.
Article
Materials Science, Multidisciplinary
S. H. Florez, C. Papusoi, P. Mani, M. Desai
Summary: Microstructural segregation was demonstrated in oxide containing [Co/Pt](n) superlattice films with strong perpendicular magnetic anisotropy for high-density magnetic recording media. By adding optimized mixtures of oxides into the Co and Pt layers, films with columnar grains, similar to 8nm grain pitch, and controlled intergranular exchange were achieved. The magnetic, microstructural, and crystal properties of these films were studied as a function of Pt thickness and oxide content.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Physical
Dimitrios I. Anyfantis, Camillo Ballani, Nikos Kanistras, Alexandros Barnasas, Ioannis Tsiaoussis, Georg Schmidt, Evangelos Th. Papaioannou, Panagiotis Poulopoulos
Summary: Co/CoO multilayers were fabricated using radio-frequency magnetron sputtering. Platinum was used as buffer and capping layers, as well as an ultrathin intermediate layer to enhance perpendicular magnetic anisotropy. Three samples were compared based on magnetic anisotropies and exchange bias. The use of a magnetic substrate resulted in loops with large remanence and significant exchange bias. These samples have potential applications in spintronics and magnetic storage.
Article
Materials Science, Multidisciplinary
Minghua Li, Zhuoyao Liu, Yu Chen, Hongming Liang, Yantai Liu, Jingran Jia, Hui Shi, Guanghua Yu
Summary: This study systematically investigates the effect of Al2O3 insertions on the thermal stability of [Pt(1)/Al2O3(t)/Co(0.4)](3) films. The study found that inserting a thin Al2O3 at the Pt/Co interface can limit interdiffusion, leading to increased perpendicular magnetic anisotropy and decreased coercivity. Additionally, the Al2O3 insertions react with the metal to form oxides, further enhancing the magnetic anisotropy.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Jie Qi, Yunchi Zhao, Haochang Lyu, Guang Yang, He Huang, Jingyan Zhang, Jianxin Shen, Weidu Qin, Chaoqun Hu, Yang Gao, Yaqin Guo, Bokai Shao, Yi Zhang, Zhaozhao Zhu, Hongxiang Wei, Baogen Shen, Shouguo Wang
Summary: By introducing a 2-monolayer Cr insertion between layers, a twinning structure of the 7-ML ferromagnetic Co layer can be achieved, leading to a significant enhancement of Hall resistivity. Analysis of the crystalline structures suggests that the dominant contribution to Hall resistivity comes from skew scattering, with the remarkable enhancement of p(xy) attributed to the specific twinning structure.
Article
Physics, Applied
SK. Ramjan, L. S. Sharath Chandra, Rashmi Singh, P. Ganesh, Archna Sagdeo, M. K. Chattopadhyay
Summary: This study demonstrates that yttrium in immiscible and forms precipitates of various sizes in the body centered cubic V0.6Ti0.4 alloy superconductor. The number and size of precipitates depend on the amount of yttrium added. The addition of yttrium creates a large amount of line disorders that effectively pin the magnetic flux lines. The superconducting transition temperature increases with the increasing amount of yttrium, while the maximum critical current density is observed in the alloy containing 2% yttrium, exceeding that of the parent alloy by more than 7.5 times in fields higher than 1 T.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Ratnesh Gupta, K. Sangeeth, M. Gupta, R. J. Choudhary, A. Sagdeo, F. Singh, Ajay Gupta
Summary: The FeCo/CoO bilayer shows exchange bias at 10K, with the value being enhanced by thermal annealing. X-ray diffraction confirms the phase formation in the CoO layer, and a correlation is observed between soft X-ray absorption and magnetic characteristics. Ion irradiation affects the exchange bias value, with higher ion fluence reducing the value due to defects in the film.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Physics, Applied
Manik Kuila, Archna Sagdeo, Lanuakum A. Longchar, R. J. Choudhary, S. Srinath, V. Raghavendra Reddy
Summary: Ce:YIG epitaxial thin films were prepared on GGG substrates, and it was found that the films grown on GGG(111) substrates exhibited perpendicular magnetic anisotropy. The developed PMA was confirmed by various measurements and magnetic bubble domains were observed. The observed PMA was explained by the growth direction of the films and the interplay of magnetic anisotropy terms. It was also found that the PMA could be tuned with film thickness and exhibited remarkable temperature stability on GGG(111) substrates.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Arunchandran Chenan, J. Jyothymol, S. Abirami, Venkataramana Bonu, Harish C. Barshilia
Summary: The corrosion resistance properties of Ti/TiN and TiAl/TiAlN nanolayered multilayered coatings deposited on Ti6Al4V alloy substrates were investigated. The coatings had a bi-layer thickness of approximately 3.5 nm/4 nm and a total thickness of approximately 9 μm. Electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion properties of the coatings immersed in 3.5 wt% NaCl solution for 30 days. The EIS investigation revealed that corrosion occurred due to the penetration of electrolyte and oxygen through the micro/nanopores present in the coatings. It was found that the TiAl/TiAlN coating offered superior corrosion protection compared to the Ti/TiN coating during the immersion study. Potentiodynamic polarization studies showed that both coatings exhibited passive behavior, with the formation of a passive film enhancing the barrier properties and providing anodic protection to the underlying alloy.
Article
Materials Science, Multidisciplinary
Shankar Dutt, Omkar Rambadey, Pankaj R. Sagdeo, Archna Sagdeo
Summary: The exceptional performance of organic-inorganic metal halide perovskites as photovoltaics can be attributed to their unique properties such as high absorption coefficient and tunable band gap. The presence of ferroelectricity in the system is believed to assist charge separation and increase efficiency, but there is a debate among researchers regarding their structures and ferroelectric nature. This study on MAPbCl3 single crystals shows through various measurements that the organic-inorganic metal halide sample is not ferroelectric and has a non-polar structure throughout the studied temperature range. These results resolve the controversy in the existing literature regarding the ferroelectric behavior of organic-inorganic metal halide perovskites.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Physics, Applied
Kritika Vijay, L. S. Sharath Chandra, Kawsar Ali, Archna Sagdeo, Pragya Tiwari, M. K. Chattopadhyay, A. Arya, Soma Banik
Summary: Topological quantum phenomena arise in Kagome semimetal CoSn due to the presence of Dirac fermions and flat bands, which result in novel transport properties. By doping Fe in CoSn, we investigated the magnetotransport and electronic properties. A large positive magnetoresistance (MR) of approximately 105% at 3K and 8T magnetic field was observed in CoSn. Fe doping in Co1-xFexSn leads to negative MR, with a large negative value for x = 0.2 (-8.4%), which decreases for x = 0.3 (-3.7%) and x = 0.4 (-2.7%). The tunability of MR properties in Co1-xFexSn is attributed to the changes in energy position of the localized flat band and the emergence of quasi-localized states near the Fermi level.
APPLIED PHYSICS LETTERS
(2023)
Article
Energy & Fuels
Shrirang M. M. Pathak, V. Praveen Kumar, Venkataramana Bonu, Leon Mishnaevsky Jr, R. V. Lakshmi, Parthasarathi Bera, Harish C. C. Barshilia
Summary: Wind energy is considered a clean energy source and efforts are being made to protect wind turbine blades from erosion caused by various factors. It is also important to address the waste produced in turbine fabrication and end-of-life phases. In this study, cellulose microparticles and microfibers were used to reinforce water-based polyurethane coatings, resulting in improved erosion resistance.
Article
Materials Science, Multidisciplinary
Pooja Pant, Harshit Agarwal, Suresh Bharadwaj, Sachin Srivastava, Archna Sagdeo, M. A. Shaz
Summary: The effect of improved dielectric properties in the presence of an applied magnetic field is discussed in poly-crystalline Gd0.55Pr0.45MnO3 complemented by the structural and magnetic properties. Enhanced dielectric permittivity and low dielectric loss represent the strongly field-dependent dielectric behavior of the sample. The structural characterizations confirm the orthorhombic symmetry and lack of structural transition at lower temperatures.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
M. Shreevalli, Ran Vijay Kumar, Divakar Ramachandran, C. Padmaprabu, V Karthik, Archna Sagdeo
Summary: The microstructural changes induced by neutron irradiation in different variants of austenitic stainless steels were characterized using the ADXRD technique. The effect of irradiation-induced defects on X-ray diffraction peak profile parameters was quantified and correlated with dislocation density. Peak broadening increased with increasing displacement damage levels in most cases. Lattice contraction was observed in SS 304 L(N) and SS 316, while lattice expansion was exhibited in SS 316 L(N). The increase in yield strength was related to the dislocation density, with saturation observed in SS 304 L(N) and linear behavior in SS 316 L(N).
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Multidisciplinary Sciences
Kritika Vijay, Durga Sankar Vavilapalli, Ashok Arya, S. K. Srivastava, Rashmi Singh, Archna Sagdeo, S. N. Jha, Kranti Kumar, Soma Banik
Summary: The idea of manipulating spins in magnetic two-dimensional van der Waal materials through strain has led to the development of new generation spintronic devices. Magneto-strain effects arise due to thermal fluctuations and magnetic interactions, influencing the lattice dynamics and electronic bands. In this study, the mechanism of magneto-strain effects in CrGeTe3, a vdW material, across the ferromagnetic transition is investigated. It is found that an isostructural transition occurs in CrGeTe3 with lattice modulation during the ferromagnetic ordering. The in-plane lattice contraction leads to magnetocrystalline anisotropy, while the electronic structure exhibits band shifts, broadening, and twinned bands in the ferromagnetic phase.
SCIENTIFIC REPORTS
(2023)
Article
Nanoscience & Nanotechnology
Ramarajan Ramanathan, Selvakumar Nagarajan, Venkataramana Bonu, Priyanka Patel, Shubhangi Jamdar, Harish C. Barshilia, Ramesh Chandra Mallik
Summary: Thin film technology offers possibilities and advancements in gas sensor devices. Sb-doped nanometer thin-SnO2 films were developed for CO/NH3 gas detection. The structural, surface, optical, and resistivity properties were investigated as a function of film thickness. ATO thin films showed enhanced response towards CO/NH3 gas detection with better stability and selectivity for CO gas. The results indicate the potential application of nanometer ATO films for enhanced gas detection.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
S. Silpa, G. Srinivas, Arup Biswas, Harish C. Barshilia, Vinayak B. Kamble
Summary: Tapping the potential of solar thermal energy requires spectrally selective solar absorber coatings, which lead to high photothermal efficiency. Micro-cavities are known to dramatically enhance or suppress light absorption and emission in a directional manner and are used in nanophotonics, photodetectors, lasing, etc.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
A. Tripathy, K. Gautam, K. Dey, S. R. Sahu, A. Ahad, A. Upadhyay, A. Sagdeo, S. Francoual, P. J. Bereciartua, I. Gudim, J. Strempfer, V. G. Sathe, D. K. Shukla
Summary: Rare-earth iron borates have attracted considerable interest due to their complex structural and magnetic properties. In this study, the structural phase transition and element-specific magnetic ordering behavior of Ho0.5Nd0.5Fe3(BO3)4 below its antiferromagnetic transition temperature are investigated. The results indicate that the spontaneous electric polarization in this compound emerges through the p-d hybridization mechanism associated with the FeO6 octahedra.
Article
Energy & Fuels
Deepanjana Adak, Poulami Mondal, Raghunath Bhattacharyya, Sandip Bysakh, Harish C. Barshilia
Summary: In this study, a durable superhydrophilic coating with photocatalytic and anti-reflecting properties was successfully prepared by sol-gel-based block copolymers assisted evaporation-induced self-assembly (EISA) method. The coating showed outstanding mechanical durability, good water contact angle, photo-catalytic capabilities, improved optical transmittance, and reduced refractive index value.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Materials Science, Multidisciplinary
Soma Banik, Kritika Vijay, Suvankar Paul, Najnin Mansuri, D. K. Shukla, S. K. Srivastava, Archna Sagdeo, Kranti Kumar, Shilpa Tripathi, S. N. Jha
Summary: This study reveals that the spin reorientation transition in Nd2CuO4 is caused by electronic interactions between the bulk and the surface. The presence of Nd2+ states on the surface, resulting from electron-like doping, leads to ferromagnetic correlations and a decrease in the spin reorientation energy gap. Furthermore, the interaction between Nd3+ and Nd2+ states through the Cu-O spin cloud explains the drastic variation in density of states and valence band narrowing observed at low temperatures. Additionally, the bound polaronic states in Nd2CuO4 exhibit short range electron-lattice interaction and a large negative Seebeck coefficient, suggesting its potential as a thermoelectric material.
MATERIALS ADVANCES
(2022)