Article
Physics, Multidisciplinary
Jean-Come Philippe, Alexis Lespinas, Jimmy Faria, Anne Forget, Dorothee Colson, Sarah Houver, Maximilien Cazayous, Alain Sacuto, Indranil Paul, Yann Gallais
Summary: Anisotropic strain selectively affects the role of nematic fluctuations in promoting superconductivity. Our results confirm the significance of nematic fluctuations in electron pairing.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Qiang Zou, Mingming Fu, Zhiming Wu, Li Li, David S. Parker, Athena S. Sefat, Zheng Gai
Summary: Electronic inhomogeneities in Co, Ni, and Cr doped BaFe2As2 single crystals were compared in different bulk property regions. Machine learning was used to categorize the inhomogeneous electronic states, revealing different origins and roles. While the relative percentages of electronic states varied in different samples, the total volume fractions were similar.
NPJ QUANTUM MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Jaafar N. Ansari, Karen L. Sauer, Igor I. Mazin
Summary: In this study, the effect of Co doping on the real-space nematic fluctuations in BaFe2As2 is investigated by combining nuclear magnetic resonance data with first-principles calculations. It is found that the dynamics of nematic fluctuations are exceptionally slow even in the formally tetragonal phase.
Article
Physics, Multidisciplinary
Haruyasu Sato, Mitsuhiro Akatsu, Ryosuke Kurihara, Yoshiaki Kobayashi, Yuichi Nemoto
Summary: The critical properties originating from degenerate orbitals at the ferro-quadrupole quantum critical point (QCP) in the iron pnictide superconductor Ba(Fe1-xCox)2As2 were investigated through ultrasonic experiments. The temperature dependence of various parameters, such as the elastic soft mode C66, Jahn-Teller energy Delta Q, Weiss temperature Theta Q, and hexadecapole susceptibility ultrasonic attenuation coefficient alpha 66, near the QCP were found to exhibit significant changes. The unconventional critical exponent z nu was observed to be 3 near the QCP, suggesting enhanced quantum fluctuations. These observations indicate the potential key role of order parameter fluctuations in the superconductivity.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Teklie Lissanu Tegegne, Gebregziabher Kahsay
Summary: This study investigated the mathematical expressions of temperature and angle dependence of magnetic fields and Ginzburg-Landau characteristics in iron-based superconductors. Phase diagrams were plotted based on experimental values, showing the relationship between various parameters with temperature and angle variations. The theoretical investigation was found to be consistent with the obtained experimental results.
JOURNAL OF MAGNETICS
(2021)
Article
Materials Science, Multidisciplinary
Guannan Chen, Anuva Aishwarya, Mark R. Hirsbrunner, Jorge Olivares Rodriguez, Lin Jiao, Lianyang Dong, Nadya Mason, Dale Van Harlingen, John Harter, Stephen D. Wilson, Taylor L. Hughes, Vidya Madhavan
Summary: The monolayer films of Fe (Se,Te) on Bi2Te3 exhibit multi-gap superconducting states similar to the bulk, and a unique pattern of sign changes not observed in the bulk has been discovered. This work establishes monolayer Fe (Se,Te)/Bi2Te3 as a robust multi-band unconventional superconductor and provides a platform for exploring non-trivial topology in this highly-tunable system.
NPJ QUANTUM MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Vachagan Harutyunyan, Aram Sahakyan, Andranik Manukyan, Bagrat Grigoryan, Hakob Davtyan, Ashot Vardanyan, Christopher J. Rhodes, Vika Arzumanyan
Summary: The introduction rates of electrically active radiation defects in n-type and p-type Si semiconductor crystals were studied by proton irradiation, and it was found that the concentration of radiation defects can be described by an exponential function. The introduction rate of radiation defects is higher for proton irradiation compared to electron irradiation. Samples with a low introduction rate of defects are more resistant to particle irradiation. Proton irradiation has little effect on the charge carrier mobility in silicon crystals, while electron irradiation leads to significant decreases. Furthermore, the resistivity of silicon crystals increases exponentially with the level of radiation fluence under proton irradiation.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Patrick Pearson, Jan Keller, Jes Larsen, Volodymyr Kosyak, Charlotte Platzer-Bjorkman
Summary: In 2017, CIGS, CZTS, and CZTSSe thin film solar cells were irradiated by 3 MeV protons to study their radiation hardness and recovery. CZTS and CZTSSe showed better resistance and recovery in terms of performance compared to CIGS. However, in a later investigation in 2021, while CZTSSe fully recovered from radiation damage, it exhibited aging-related degradation.
Article
Astronomy & Astrophysics
Khusniddin K. Olimov, Fu-Hu Liu, Kobil A. Musaev, Maratbek Z. Shodmonov
Summary: This study investigates the dependence of midrapidity p(t) distributions of charged pions and kaons, protons, and antiprotons on charged-particle multiplicity density in proton-proton collisions at 7 TeV at the LHC. The results show that the effective temperatures increase with increasing charged-particle multiplicity, in agreement with similar results in collisions at 13 TeV. The study also observes a power dependence between the initial energy density and effective temperature, as well as the emergence of transverse radial flow in the collisions at 7 TeV.
Article
Physics, Nuclear
Khusniddin K. Olimov, Fu-Hu Liu, Kobil A. Musaev, Kosim Olimov, Boburbek J. Tukhtaev, Bekhzod S. Yuldashev, Nasir Sh. Saidkhanov, Kobil I. Umarov, Kadyr G. Gulamov
Summary: The study analyzed the multiplicity dependencies of midrapidity pt spectra of identified charged particles in inelastic p+p collisions at 13 TeV at the LHC. It was found that with an increase in multiplicity, the effective temperatures T increased consistently, and the transverse flow became significant at higher multiplicity events. The probable onset of deconfinement phase transition was estimated to occur at an average charged-particle multiplicity density of approximately 7.1 +/- 0.2.
INTERNATIONAL JOURNAL OF MODERN PHYSICS A
(2021)
Article
Physics, Applied
Russell Giannetta, Antony Carrington, Ruslan Prozorov
Summary: The London penetration depth λ is crucial for understanding electromagnetic behavior in superconductors. Measurements of λ as a function of temperature, field, and impurity scattering have helped reveal the nature of order parameter and pairing interactions. The tunnel-diode resonator technique has been widely adopted worldwide as a precision tool for exploring new superconductors.
JOURNAL OF LOW TEMPERATURE PHYSICS
(2022)
Article
Physics, Applied
Chaowei Hu, Makariy A. Tanatar, Ruslan Prozorov, Ni Ni
Summary: MBT is the first intrinsic magnetic topological insulator and can be made ferromagnetic through specific methods. We studied the magnetic dynamics of several ferromagnetic MBT compounds and found a universal slow relaxation behavior, attributing it to irreversible domain movements. The soft nature of ferromagnetic domains was revealed by our magneto-optical measurements.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Condensed Matter
Ruslan Prozorov, Sergey L. Bud'ko, Paul C. Canfield
Summary: This study reports the observation of rectangular cross-section tubular ferromagnetic domains in thick single crystals of CeAgSb2 in zero applied field. The formation of closed-topology patterns is facilitated by the relatively low exchange energy, small net magnetic moment, and anisotropic in-plane crystal electric fields. The tubular domain structure irreversibly transforms into a dendritic pattern upon cycling the magnetic field, resulting in a 'topological magnetic hysteresis'.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Applied
D. Torsello, D. Gambino, L. Gozzelino, A. Trotta, F. Laviano
Summary: We investigated the expected neutron damage in high-temperature superconducting tapes used in compact fusion reactors. Monte Carlo simulations were performed to obtain the neutron spectrum and fluence at the magnet position, which were then used to calculate the energy distributions of primary knock-on atoms for each atomic species in the superconductor. Molecular dynamics simulations were used to characterize the displacement cascades in terms of size and morphology. The expected radiation environment was compared with the neutron spectrum and fluences achievable in current experimental facilities to identify similarities and differences that are relevant to the understanding of radiation hardness of these materials in real fusion conditions. Our findings show that different neutron spectra result in different damage regimes, irradiation temperature influences the number of defects generated, and neutron-superconductor interaction leads to local temperature increase. These observations suggest the need for further experimental investigations in different conditions and the necessity of neutron shielding in compact fusion reactors.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
M. Fracasso, F. Gomory, M. Solovyov, R. Gerbaldo, G. Ghigo, F. Laviano, S. Sparacio, D. Torsello, L. Gozzelino
Summary: In this study, the flux-jump occurrence in an MgB2 cup-shaped shield was numerically investigated using the finite element method and the COMSOL 6.0 Multiphysics (R) software. The computed shielding curves showed a good agreement with experimental data at different temperatures and positions. The validated model was then used to explore optimization routes by improving the thermal conductivity of the material and the thermal exchange between the device and the cooling stage.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Gianluca Ghigo, Daniele Torsello, Laura Gozzelino, Michela Fracasso, Mattia Bartoli, Cristian Pira, Davide Ford, Giovanni Marconato, Matteo Fretto, Ivan De Carlo, Nicola Pompeo, Enrico Silva
Summary: This study characterizes NbTi films operating at approximately 11 GHz and in DC magnetic fields up to 4 T using the coplanar waveguide resonator technique. It provides quantitative information about the penetration depth, complex impedance, and vortex-motion-induced complex resistivity. This characterization is crucial for the development of radiofrequency cavity technology.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Analytical
Silvia Zecchi, Fabrizio Ruscillo, Giovanni Cristoforo, Mattia Bartoli, Griffin Loebsack, Kang Kang, Erik Piatti, Daniele Torsello, Gianluca Ghigo, Roberto Gerbaldo, Mauro Giorcelli, Franco Berruti, Alberto Tagliaferro
Summary: By mixing red mud with hemp waste, biochar with high conductivity and good magnetic properties can be produced through carbothermal processes. The resulting biochar enriched with thermally-reduced red mud is then used to prepare epoxy-based composites, which are tested for their electric and magnetic properties.
Article
Nanoscience & Nanotechnology
Elham Sharifikolouei, Antoni Zywczak, Baran Sarac, Tomasz Koziel, Reza Rashidi, Piotr Bala, Michela Fracasso, Roberto Gerbaldo, Gianluca Ghigo, Laura Gozzelino, Daniele Torsello
Summary: In this study, Fi(40)Ni(40)B(20) metallic glass microfibers with a diameter of 5 μm were fabricated, and the influence of different melt-spinning wheel velocities on their structure and magnetic properties was investigated. Cylindrical magnetic field shields with anisotropic static field shielding behavior were obtained by wrapping the microfibers around a cast. Moreover, embedding the microfibers in an epoxy matrix significantly improved the electromagnetic properties of the composite at GHz frequencies.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Brinda Kuthanazhi, Kamal R. Joshi, Sunil Ghimire, Erik Timmons, Elena Gati, Li Xiang, Ruslan Prozorov, Sergey L. Bud'ko, Paul C. Canfield
Summary: EuCd2As2 is an antiferromagnetic semimetal that can undergo changes in its magnetic state and properties through Ag and Na doping. Temperature-substitution phase diagrams were constructed and showed the splitting of the magnetic transition into two different transitions. It was observed that Ag and Na doping stabilized a magnetic state with a net ferromagnetic moment. This study demonstrates that chemical substitution and changes in band filling can be used to tune the magnetic ground state and stabilize a ferromagnetic phase in EuCd2As2.
PHYSICAL REVIEW MATERIALS
(2023)
Review
Energy & Fuels
Samuele Meschini, Francesco Laviano, Federico Ledda, Davide Pettinari, Raffella Testoni, Daniele Torsello, Bruno Panella
Summary: This paper provides a comprehensive overview of nuclear fusion concepts for industrial applications, with a focus on the private sector. The designs are classified into three leading concepts: magnetic confinement, inertial confinement, and magneto-inertial confinement. The working principles of the main devices are described in detail, highlighting the strengths and weaknesses of each design. The importance of the public sector in private projects, technological maturity, and main criticalities of each project are also discussed. Additionally, the geographical distribution of companies and public institutions pursuing fusion device designs for commercial applications is reported.
FRONTIERS IN ENERGY RESEARCH
(2023)
Review
Physics, Applied
Erik Piatti, Daniele Torsello, Gianluca Ghigo, Dario Daghero
Summary: The iron-based compounds of the 12442 family, which originate from the intergrowth of 122 and 1111 building blocks, display unique properties and are similar to double-layer cuprates. Investigating their superconducting properties, particularly the order parameter symmetry, is crucial in understanding their relationship to cuprates. In this study, the authors compare their measurements in Rb-12442 with those from the literature and find that the compound possesses at least two gaps, one of which is nodal. The compatibility of these findings with theoretical models and previous results is thoroughly discussed.
LOW TEMPERATURE PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Erik Piatti, Daniele Torsello, Gaia Gavello, Gianluca Ghigo, Roberto Gerbaldo, Mattia Bartoli, Donatella Duraccio
Summary: The combination of conductive carbon and magnetic particles is an effective strategy to produce advanced fillers for polymer composites that can shield against microwave radiation. In this study, an iron-tailored biochar obtained from olive pruning pyrolysis was developed and characterized as a filler for epoxy composites. Extensive characterization was conducted to evaluate the electrical and magnetic properties of biochar-based composites with and without iron. The results showed that the composites with higher filler loading exhibited higher DC electrical conductivity and ferromagnetic behavior.
