Article
Materials Science, Ceramics
Dongwen Gao, Li Wang, Xueqiong Su
Summary: This study investigates the influence of different doping ratios on the composition, structure, morphology, and luminescence properties of bulk ceramics, determining the optimum doping ratio in this range. The research enhances the optical performance of the material, suggesting improved microstructural, optical, and electrical properties for potential use in new optoelectronic devices.
CERAMICS INTERNATIONAL
(2021)
Article
Multidisciplinary Sciences
Seokbae Lee, Yu-Seong Seo, Seulki Roh, Dongjoon Song, Hiroshi Eisaki, Jungseek Hwang
Summary: We investigated the properties of K-doped BaFe2As2 single crystals using infrared spectroscopy. We obtained the superfluid plasma frequencies and London penetration depths from the measured optical conductivity spectra. The electron-boson spectral density functions were also extracted in the superconducting state. By analyzing the extracted spectral density functions, we determined the maximum superconducting transition temperatures and calculated the superconducting coherence lengths. We found similarities and differences in the doping-dependent superconducting quantities between K-doped BaFe2As2 and hole-doped cuprates. The obtained superconducting properties across a wide doping range will provide valuable information for understanding the microscopic pairing mechanism in Fe-pnictide superconductors.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Golam Murtaza Mirza, Mahamud Hasan Tusher, Nazmus Sakib, Naymul Islam
Summary: The surface morphology, structure, and optical characteristics of undoped and Al-doped ZnO thin films were investigated. Thin films were prepared on glass substrates using the sol-gel spin-coating technique, with Al-doping concentrations of 1.5% and 2.5%. Structural analysis revealed a decrease in grain size and an increase in dislocation density after adding Al dopants. Scanning electron microscopy data showed that undoped ZnO particles were spherical and agglomerated, while the particle size decreased and transmittance decreased with increasing Al-dopant concentration according to the related histograms and distribution curve. Additionally, band gaps of the films were observed to decrease with increasing Al-dopant percentage.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Lanting Feng, Zhe Liu, Mingfeng Zhu, Yisong Zheng
Summary: The conductivity of ABA-stacked trilayer graphene is smaller than that of monolayer graphene due to strong interband scattering. This is despite the fact that the trilayer graphene has an additional parabolic dispersion band.
Article
Multidisciplinary Sciences
Dogyeong Kim, Sol Lee, Jiwon Park, Jinho Lee, Hee Cheul Choi, Kwanpyo Kim, Sunmin Ryu
Summary: Understanding the nature of molecular excitons in low-dimensional molecular solids and their spatial evolution is crucial for fundamental photophysics and various applications. In this study, the authors demonstrate the in-plane and out-of-plane excitonic evolution by assembling two-dimensional perylene crystals on hexagonal boron nitride crystals. The findings provide important insights into low-dimensional molecular systems.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Jian Zhang, Yi Zhu, Mike Tebyetekerwa, Delong Li, Dan Liu, Weiwei Lei, Lifeng Wang, Yupeng Zhang, Yuerui Lu
Summary: Substitutional doping of monolayer transition metal dichalcogenides (TMDs) with vanadium has been successfully achieved, resulting in significant enhancement of photoluminescence (PL) intensity and dominance of exciton recombination over trion recombination. Controllable vanadium doping allows for tuning of optical bandgap of MoS2 and threshold voltage of field-effect transistors (FETs). This study demonstrates the potential for applications in optoelectronics by preparing Mo-based monolayer TMDs with controllable vanadium doping.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Fei Jia, Shuang Zhao, Jing Wu, Ling Chen, Te-Huan Liu, Li-Ming Wu
Summary: This study reports a unique ternary sulfide compound, Cu3BiS3, with ultralow thermal conductivity. By using DFT calculations and analysis, researchers found that the Cu atoms in Cu3BiS3 are coordinated in a two-dimensional triangular arrangement, leading to efficient out-of-plane phonon scattering and reduced thermal conductivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Physics, Multidisciplinary
S. Mironov, A. S. Mel'nikov, I. D. Tokman, V. Vadimov, B. Lounis, A. Buzdin
Summary: This study investigates the temperature-dependent dc magnetic moment of Cooper pairs in superconducting condensates under the effect of circularly polarized electromagnetic radiation. The light-induced magnetic moment is influenced by the oscillatory contribution to the superconducting order parameter dynamics, which is due to the nonzero imaginary part of the GL relaxation time. The connection between the direct and inverse Faraday phenomena is established through the relevance of the GL relaxation time to the Hall effect in the superconducting state.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
A. Miquelot, L. Youssef, C. Villeneuve-Faure, N. Prud'homme, N. Dragoe, A. Nada, V Rouessac, S. Roualdes, J. Bassil, M. Zakhour, M. Nakhl, C. Vahlas
Summary: The study investigated the morphological characteristics and electrical properties of TiO2 films obtained by MOCVD and PECVD, with the latter including nitrogen doping. The increase in nitrogen amount in the PECVD films enhances disorder in their pillar-like columnar morphology. A transition from dense to tree-like columnar morphology is observed for the MOCVD films with increasing deposition temperature.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Dabao Lu, Zhufeng Hou, Huimin Li, Bo Da, Z. J. Ding
Summary: The study demonstrates that even a single hydrogen atom in out-of-plane passivation can significantly impact plasmon excitation, as well as the distribution of induced charge density and hot carriers. This phenomenon is observable even in hexagonal nanographene with a size of 2.0 nm.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
M. A. Wederni, W. Hzez, A. Rached, R. Meftah, H. Rahmouni, K. Khirouni, S. Alaya, R. J. Martin-Palma
Summary: This study focuses on the development of novel lead-free materials that can replace lead-based compounds in high-temperature devices. By partially replacing Bi ions in Bi4Ti3O12 with Yb and Er, the researchers aimed to improve the material's physical properties. By adjusting the Yb content, they were able to control the conductivity, impedance, and permittivity of the material at different temperatures, opening up new possibilities for its application.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Condensed Matter
T. E. Ada, K. N. Nigussa, L. D. Deja
Summary: This study investigates the structural and optical properties of doping of bismuth-ferrite using density functional theory. Different geometric structures are obtained by doping with selected Alkali and Alkaline-earth metals. The electronic band gaps of the structures are calculated, and they appear to have an influence on the optical properties. The dopings result in a change in the refractive, reflective, and absorbance properties of the perovskite, with Li-Ba co-doping showing enhanced absorption capacity and multiferroic property.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Wenyuan Li, Xiaojun Yan, Xing Zou, Lili Liu, Shifa Wang, Yong Wei, Xinyi Yang, Lei Hu, Yuming Feng, Wencai Yi
Summary: This work systematically studies the 2D alpha-In2O3 monolayer and finds that it has a stable configuration and good oxidation resistance. It is identified as a semiconductor with a direct bandgap of 1.41 eV, making it a promising candidate for modern gate technologies. The alpha-In2O3 monolayer also exhibits excellent optical absorption coefficient and superior out-of-plane piezoelectric response, making it useful for field-effect phototransistors and out-of-plane piezoelectric devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Prashant Chauhan, Ramesh Budhani, N. P. Armitage
Summary: This study uses time-domain terahertz spectroscopy to measure the frequency response of beta-tungsten thin film and finds that the superconducting gap and superfluid spectral weight are much smaller than expected. The possibility of other tungsten allotropes is ruled out, suggesting that the topological surface states of beta-tungsten may be responsible for the observed inhomogeneity.
Article
Energy & Fuels
Chambakkoottathil Soumya, Puthiya Purayil Pradyumnan
Summary: The effect of dual substitution of indium and nickel on the structural and morphological deformation of zinc oxide and its enhancement of thermoelectric properties were investigated. The doped materials showed a similar hexagonal wurtzite structure to the host material, with increased crystallite size and strain due to the inclusion of cations with larger radius. The optical band gap energy decreased, leading to higher charge carrier density and improved transport properties. The doped samples exhibited highest electrical conductivity and seebeck coefficient, resulting in an increased power factor, while the thermal conductivity decreased. The highest figure of merit obtained was 0.11.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Physics, Multidisciplinary
BoWen Li, WenChao Jiang, GuanYu Chen, Ying Xiang, Wei Xie, YaoMin Dai, XiYu Zhu, Huan Yang, Hai-Hu Wen
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2020)
Article
Chemistry, Physical
N. Sirica, P. P. Orth, M. S. Scheurer, Y. M. Dai, M-C Lee, P. Padmanabhan, L. T. Mix, S. W. Teitelbaum, M. Trigo, L. X. Zhao, G. F. Chen, B. Xu, R. Yang, B. Shen, C. Hu, C-C Lee, H. Lin, T. A. Cochran, S. A. Trugman, J-X Zhu, M. Z. Hasan, N. Ni, X. G. Qiu, A. J. Taylor, D. A. Yarotski, R. P. Prasankumar
Summary: Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies. Topological materials, like topological semimetals, are particularly sensitive to changes in time-reversal and crystalline symmetries, affecting both bulk and surface electronic states. The study demonstrates ultrafast symmetry breaking using optically driven photocurrents.
Article
Materials Science, Multidisciplinary
V. S. Bhadram, B. Joseph, D. Delmonte, E. Gilioli, B. Baptiste, Y. Le Godec, R. P. S. M. Lobo, A. Gauzzi
Summary: Through experiments under hydrostatic pressure, this study investigated the structural stability of the quadruple perovskite LaMn7O12 and discovered a first-order structural phase transition, indicating the potential for a purely electronic insulator-metal transition.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Multidisciplinary Sciences
Gan Liu, Xinran Ma, Kuanyu He, Qing Li, Hengxin Tan, Yizhou Liu, Jie Xu, Wenna Tang, Kenji Watanabe, Takashi Taniguchi, Libo Gao, Yaomin Dai, Hai-Hu Wen, Binghai Yan, Xiaoxiang Xi
Summary: Unusual large-frequency collective lattice excitations, known as amplitude modes, are observed in CsV3Sb5, a Kagome metal, in the absence of phonon softening, providing evidence of strong electron-phonon coupling.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Adrien Gourgout, Maxime Leroux, Jean-Loup Smirr, Maxime Massoudzadegan, Ricardo P. S. M. Lobo, David Vignolles, Cyril Proust, Helmuth Berger, Qiang Li, Genda Gu, Christopher C. Homes, Ana Akrap, Benoit Fauque
Summary: In this study, it was found that electron doped ZrTe5 undergoes a metal-insulator transition at low temperature when a magnetic field confines the electron gas in its lowest spin-polarised Landau level. This transition is accompanied by a sign change of the Hall and Seebeck effects. The reduction of charge carrier density due to magnetic freeze-out on ionized impurities leads to an anomalous Hall response of the spin-polarised electrons in this Dirac metal with a tiny Fermi energy, extremely narrow band gap, and large g-factor.
NPJ QUANTUM MATERIALS
(2022)
Article
Physics, Condensed Matter
Bing Yao, Weilin Liu, Xiaoxiang Zhou, Jiangfeng Yang, Xianlei Huang, Zihao Fu, Guowen Yuan, Yuefeng Nie, Yaomin Dai, Jie Xu, Libo Gao
Summary: In this study, large-scale Cr2S3 and Cr2Se3 films with controllable thickness were successfully grown and their crystalline qualities were confirmed. The thickness-dependent Raman vibrations were systematically investigated, showing a slight redshift with increasing thickness. The 1.9 nm thick Cr2S3 and Cr2Se3 films exhibited narrow optical bandgap and different electrical properties.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Xiaoxiang Zhou, Yongkai Li, Xinwei Fan, Jiahao Hao, Ying Xiang, Zhe Liu, Yaomin Dai, Zhiwei Wang, Yugui Yao, Hai-Hu Wen
Summary: In the study of AV3Sb5, it was found that the CDW gap ACDW increases with the increase in alkali-metal atom radius from K to Cs, while TCDW first rises and then drops, failing to establish a scaling relation with ACDW. The observed enhancement of electronic correlations in CsV3Sb5 suppresses the CDW but enhances SC, suggesting that electronic correlations play an important role in manipulating the CDW and its entanglement with SC in AV3Sb5.
Article
Materials Science, Multidisciplinary
L. Cheng, F. C. Fei, H. Hu, Y. M. Dai, F. Q. Song, J. Qi
Summary: In this study, we used ultrafast optical pump-probe spectroscopy to investigate the quasiparticle dynamics in the type-II Dirac semimetal NiTe2. We observed anomalous dynamic optical responses around the critical temperature T* (-60 K), which were also confirmed by transport experiments. Specifically, our results revealed a phonon-assisted electron-hole recombination process that showed an anomaly at T* <^>' 60 K. We discovered an unusual behavior of phonon renormalization, characterized by anomalies in the temperature-dependent phonon energy and lifetime at T*. We found that these anomalies were due to the sudden shift of the phonon mode involved in the recombination, which was caused by the abrupt change in electronic structure near the Fermi surface. These findings provide deeper insights into the nonequilibrium carrier and lattice properties in topological materials.
Article
Materials Science, Multidisciplinary
Jiahao Hao, Wenshan Hong, Xiaoxiang Zhou, Ying Xiang, Yaomin Dai, Huan Yang, Shiliang Li, Huiqian Luo, Hai-Hu Wen
Summary: The optical properties of KCa2Fe4As4F2 and KCa2(Fe0.95Ni0.05)(4)As4F2 have been studied, and nodeless superconducting gaps are observed in both samples. However, the superconducting gap in K12442 suggests strong-coupling Cooper pairs, while in Ni-K12442, it supports the BCS weak-coupling pairing state. Additionally, a pseudogap is observed in K12442 at higher temperatures, while no such behavior is detected in Ni-K12442.
Article
Materials Science, Multidisciplinary
Nicholas R. Poniatowski, Tarapada Sarkar, Ricardo P. S. M. Lobo, Sankar Das Sarma, Richard L. Greene
Summary: This paper discusses the transport phenomenology of overdoped electron-doped cuprates and presents them as a clear counterexample to the putative Planckian bound, leading to serious questions about the efficacy of this bound.
Article
Materials Science, Multidisciplinary
David Santos-Cottin, Michele Casula, Luca de' Medici, F. Le Mardele, J. Wyzula, M. Orlita, Yannick Klein, Andrea Gauzzi, Ana Akrap, R. P. S. M. Lobo
Summary: The investigation on BaNiS2 reveals the electronic structure with Dirac nodal lines, showing an unusual temperature-independent isosbestic line in optical conductivity that ends at a Van Hove singularity. First-principles calculations demonstrate that this isosbestic line is associated with transitions across Dirac nodal states.
Article
Materials Science, Multidisciplinary
Xiaoxiang Zhou, Yongkai Li, Xinwei Fan, Jiahao Hao, Yaomin Dai, Zhiwei Wang, Yugui Yao, Hai-Hu Wen
Summary: This study investigates the optical properties of CsV3Sb5 at various temperatures above and below the charge-density-wave transition. The presence of multiple Drude components is observed in the low-frequency optical conductivity above the CDW transition, with distinct origins attributed to different bands in the band structure. The opening of the CDW gap affects the broad Drude component significantly while leaving the narrow Drude component unaffected, highlighting the importance of saddle point nesting in driving the CDW instability in CsV3Sb5.
Article
Materials Science, Multidisciplinary
Jiahao Hao, Xinwei Fan, Qing Li, Xiaoxiang Zhou, Chengping He, Yaomin Dai, Bing Xu, Xiyu Zhu, Hai-Hu Wen
Summary: In this study, the optical properties of Nd4Ni3O8 were investigated at different temperatures, revealing evident charge-stripe fluctuations. Optical conductivity analysis showed the presence of infrared-active phonons, far-infrared band alpha, mid-infrared band beta, and a high-energy absorption edge. The temperature-dependent optical spectral weight exhibited a T-2 law, indicating strong correlation effects.
Article
Materials Science, Multidisciplinary
Bing Xu, Y. Zhang, E. H. Alizade, Z. A. Jahangirli, F. Lyzwa, E. Sheveleva, P. Marsik, Y. K. Li, Y. G. Yao, Z. W. Wang, B. Shen, Y. M. Dai, V Kataev, M. M. Otrokov, E. Chulkov, N. T. Mamedov, C. Bernhard
Summary: This study utilized infrared spectroscopy to investigate the electronic properties of the topological antiferromagnet MnBi2Te4 and revealed the presence of two conduction bands as well as a unique increase in plasma frequency due to multiband free-carrier response. The band reconstruction below the Néel temperature led to further increases in plasma frequency and a splitting of the transition between the conduction bands, highlighting a complex and temperature-dependent multiband low-energy response with implications for surface states and device applications.
Article
Materials Science, Multidisciplinary
Eugenio Calandrini, Lorenzo Paulatto, Daniele Antonangeli, Fei He, Ricardo P. S. M. Lobo, Francesco Capitani, Jean-Blaise Brubach, Pascale Roy, Laetitia Vincent, Paola Giura
Summary: Experimental and numerical investigation of phonon optical modes of MgO were conducted at varying temperatures (300 to 1400 K) and pressures (0 to 21 GPa). Quasiharmonic approximation calculations successfully accounted for the volume dependence of optical phonon energies at high pressures, but were less accurate at larger volumes and higher temperatures. Additionally, the calculations more accurately predicted energies of transverse optical modes than longitudinal optical modes. A proposed empirical analytical expression for Z* /epsilon(infinity) as a function of atomic cell volume was based on the comparison of experimental and theoretical results. Density-functional perturbation theory including phonon-phonon scattering up to the third order effectively explained the nontrivial volume dependence of both transverse and longitudinal phonon linewidths as determined by experiments.
