12 research outputs found
Theory-guided investigation on magnetic evolution of MnPtPdP and discovery of anti-CeCoIn-type ferromagnetic MnPdP
We report the magnetic changes from canted antiferromagnetic to ferromagnetic
orderings in anti-115-type MnPtPdP ( = 1, 2, 2.5, 3, 4, and 5)
and the discovery of a new rare-earth-free ferromagnet, MnPdP by both
theoretical prediction and experimental investigation. The family compounds
were synthesized using high temperature solid state method and characterized to
crystalize in the anti-CeCoIn type with the space group P4/mmm exhibiting a
two-dimensional layered structural feature. The magnetic property measurements
indicate that the compounds ordered from canted A-type antiferromagnet in
MnPtP to ferromagnet above the room temperature with varying degrees of
coercivity and magnetic moments in MnPdP by reducing the spin orbital
coupling. The results of the MnPtPdP have been analyzed in
comparison to the other candidates of the 151 family of Mn(Pt/Pd)(P/As) to
understand the complex structure-magnetism relationships
Mn(PtPd)P: Isovalent Tuning of Mn Sublattice Magnetic Order
We report the growth and characterization of MnPdP, a ferromagnet with
T 295 K, and conduct a substitutional study with its
antiferromagnetic analogue MnPtP. We grow single crystals of MnPdP and
Mn(PtPd)P by adding Mn into (PtPd)-P based melts.
All compounds in the family adopt the layered anti-CeCoIn structure with
space group P4/mmm, and EDS and XRD results indicate that MnPtP and
MnPdP form a solid solution. Based on magnetization and resistance data, we
construct a T-x phase diagram for Mn(PtPd)P and demonstrate the
antiferromagnetic order found in MnPtP is extraordinarily sensitive to Pd
substitution. At low Pd fractions (x 0.010), the single antiferromagnetic
transition in pure MnPtP splits into a higher temperature ferromagnetic
transition followed on cooling by a lower temperature ferromagnetic to
antiferromagnetic transition and then by a re-entrant antiferromagnetic to
ferromagnetic transition at lower temperatures. The antiferromagnetic region
makes up a bubble that persists to x 0.009 for T 150 K,
with all samples x 0.009 recovering their initial ferromagnetic state with
further cooling to base temperature. Over the same low x range we find a
non-monotonic change in the room temperature unit cell volume, further
suggesting that pure MnPtP is close to an instability. Once x 0.010,
Mn(PtPd)P undergoes a single ferromagnetic transition. The
Curie temperature increases rapidly with x, rising from T 197 K
at x = 0.013 to a maximum of T 312 K for x 0.62, and
then falls back to T 295 K for pure MnPdP (x = 1). Given that
Pt and Pd are isoelectronic, this work raises questions as to the origin of the
extreme sensitivity of the magnetic ground state in MnPtP upon introducing
Pd
Observation of termination-dependent topological connectivity in a magnetic Weyl Kagome lattice
The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation program under Marie Skłodowska-Curie Grant Agreement 897276. The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (https://www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (https://www.lrz.de). The authors are grateful for funding support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project 390858490), through FOR 5249-449872909 (Project P5), and through the Collaborative Research Center SFB 1170 ToCoTronics (Project 258499086). The authors greatly acknowledge the Diamond Light Source that supported the entire micro-ARPES experiment and corresponding costs. The Flatiron Institute is a division of the Simons Foundation. P.D.C.K. and C.B. gratefully acknowledge support from The Leverhulme Trust via Grant RL-2016-006.Engineering surfaces and interfaces of materials promises great potential in the field of heterostructures and quantum matter designers, with the opportunity to drive new many-body phases that are absent in the bulk compounds. Here, we focus on the magnetic Weyl kagome system Co3Sn2S2 and show how for the terminations of different samples the Weyl points connect differently, still preserving the bulk-boundary correspondence. Scanning tunneling microscopy has suggested such a scenario indirectly, and here, we probe the Fermiology of Co3Sn2S2 directly, by linking it to its real space surface distribution. By combining micro-ARPES and first-principles calculations, we measure the energy-momentum spectra and the Fermi surfaces of Co3Sn2S2 for different surface terminations and show the existence of topological features depending on the top-layer electronic environment. Our work helps to define a route for controlling bulk-derived topological properties by means of surface electrostatic potentials, offering a methodology for using Weyl kagome metals in responsive magnetic spintronics.Publisher PDFPeer reviewe
ChatRadio-Valuer: A Chat Large Language Model for Generalizable Radiology Report Generation Based on Multi-institution and Multi-system Data
Radiology report generation, as a key step in medical image analysis, is
critical to the quantitative analysis of clinically informed decision-making
levels. However, complex and diverse radiology reports with cross-source
heterogeneity pose a huge generalizability challenge to the current methods
under massive data volume, mainly because the style and normativity of
radiology reports are obviously distinctive among institutions, body regions
inspected and radiologists. Recently, the advent of large language models (LLM)
offers great potential for recognizing signs of health conditions. To resolve
the above problem, we collaborate with the Second Xiangya Hospital in China and
propose ChatRadio-Valuer based on the LLM, a tailored model for automatic
radiology report generation that learns generalizable representations and
provides a basis pattern for model adaptation in sophisticated analysts' cases.
Specifically, ChatRadio-Valuer is trained based on the radiology reports from a
single institution by means of supervised fine-tuning, and then adapted to
disease diagnosis tasks for human multi-system evaluation (i.e., chest,
abdomen, muscle-skeleton, head, and maxillofacial neck) from six different
institutions in clinical-level events. The clinical dataset utilized in this
study encompasses a remarkable total of \textbf{332,673} observations. From the
comprehensive results on engineering indicators, clinical efficacy and
deployment cost metrics, it can be shown that ChatRadio-Valuer consistently
outperforms state-of-the-art models, especially ChatGPT (GPT-3.5-Turbo) and
GPT-4 et al., in terms of the diseases diagnosis from radiology reports.
ChatRadio-Valuer provides an effective avenue to boost model generalization
performance and alleviate the annotation workload of experts to enable the
promotion of clinical AI applications in radiology reports
Spin stiffness of chromium-based van der Waals ferromagnets
Low temperature magnetization of CrI3, CrSiTe3 and CrGeTe3 single crystals were systematically studied. Based on the temperature dependence of extrapolated spontaneous magnetization from magnetic isotherms measured at different temperatures, the spin stiffness constant (D) and spin excitation gap (Δ) were extracted according to Bloch's law. For spin stiffness, D is estimated to be 27 ± 6 meV Å2, 20 ± 3 meV Å2 and 38 ± 7 meV Å2 for CrI3, CrSiTe3 and CrGeTe3 respectively. Spin excitation gaps determined via Bloch's formulation have larger error bars yielding 0.59 ± 0.34 meV (CrI3), 0.37 ± 0.22 meV (CrSiTe3) and 0.28 ± 0.19 meV (CrGeTe3). Among all three studied compounds, larger spin stiffness value leads to higher ferromagnetic transition temperature.12 month embargo; published 23 April 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
MOS1 Negatively Regulates Sugar Responses and Anthocyanin Biosynthesis in Arabidopsis
Sugars, which are important signaling molecules, regulate diverse biological processes in plants. However, the convergent regulatory mechanisms governing these physiological activities have not been fully elucidated. MODIFIER OF snc1-1 (MOS1), a modulator of plant immunity, also regulates floral transition, cell cycle control, and other biological processes. However, there was no evidence of whether this protein was involved in sugar responses. In this study, we found that the loss-of-function mutant mos1-6 (mos1) was hypersensitive to sugar and was characterized by defective germination and shortened roots when grown on high-sugar medium. The expression of MOS1 was enhanced by sucrose. Hexokinase 1, an important gene involved in sugar signaling, was upregulated in the mos1 mutant compared to wild-type Col-0 in response to sugar. Furthermore, the mos1 mutant accumulated more anthocyanin than did wild-type Col-0 when grown on high-sugar concentration medium or under high light. MOS1 was found to regulate the expression of flavonoid and anthocyanin biosynthetic genes in response to exogenous sucrose and high-light stress but with different underlying mechanisms, showing multiple functions in addition to immunity regulation in plant development. Our results suggest that the immune regulator MOS1 serves as a coordinator in the regulatory network, governing immunity and other physiological processes
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Synthesis and physical properties of a new layered ferromagnet Cr1.21Te2
Single crystals of a new layered compound, Cr1.21Te2, were synthesized via a vapor transport method. The crystal structure and physical properties were characterized by single crystal and powder x-ray diffraction, temperature- and field-dependent magnetization, zero-field heat capacity, and angle-resolved photoemission spectroscopy. Cr1.21Te2, containing two Cr sites, crystalizes in a trigonal structure with a space group P-3 (No. 147). The Cr site in the interstitial layer is partially occupied. Physical property characterizations indicate that Cr1.21Te2 is metallic with hole pockets at the Fermi energy and undergoes a ferromagnetic phase transition at ∼173K. The magnetic moments align along the c axis in the ferromagnetic state. Based on low-temperature magnetization, the spin stiffness constant, D, and spin excitation gap, Δ, were estimated according to Bloch's law to be D=94±17meVÅ2 and Δ=0.45±0.33 meV, suggesting its possible application as a low dimensional ferromagnet
Metabolite Profiling of a Zinc-Accumulating Rice Mutant
Breeding
crops with high zinc (Zn) density is an effective way
to alleviate human dietary Zn deficiencies. We characterized a mutant
Lilizhi (LLZ) accumulating at least 35% higher Zn concentration in
grain than the wild type (WT) in hydroponic experiments. The mutant
stored less Zn content in the root and transported more Zn to the
grain. Metabolite profiling demonstrated that, with high Zn treatment,
the contents of proline, asparagine, citric acid, and malic acid were
enhanced in both LLZ and the WT, which were thought to be involved
in Zn transport in rice. Furthermore, the contents of cysteine, allothreonine,
alanine, tyrosine, homoserine, β-alanine, and nicotianamine
required for the production of many metal-binding proteins were specifically
increased in LLZ. LLZ had higher capability of amino acid biosynthesis
and metal cation transportation. The current research extends our
understanding on the physiological mechanisms of Zn uploading into
grain and provides references for further Zn biofortification breeding
in rice
Low-Temperature Fusible Silver Micro/Nanodendrites-Based Electrically Conductive Composites for Next-Generation Printed Fuse-Links
We systematically
investigate the long-neglected low-temperature
fusing behavior of silver micro/nanodendrites and demonstrate the
feasibility of employing this intriguing property for the printed
electronics application, <i>i</i>.<i>e</i>., printed
fuse-links. Fuse-links have experienced insignificant changes since
they were invented in the 1890s. By introducing silver micro/nanodendrites-based
electrically conductive composites (ECCs) as a printed fusible element,
coupled with the state-of-the-art printed electronics technology,
key performance characteristics of a fuse-link are dramatically improved
as compared with the commercially available counterparts, including
an expedient fabrication process, lower available rated current (40%
of the minimum value of Littelfuse 467 series fuses), shorter response
time (only 3.35% of the Littelfuse 2920L030 at 1.5 times of the rated
current), milder surface temperature rise (16.89 °C lower than
FGMB) and voltage drop (only 24.26% of FGMB) in normal operations,
easier to mass produce, and more flexible in product design. This
technology may inspire the development of future printed electronic
components
Mn(Pt1−xPdx)5P: Isovalent Tuning of Mn Sublattice Magnetic Order
We report the growth and characterization of MnPd5P, a rare-earth-free ferromagnet, with TC approximate to 295 K and planar anisotropy, and conduct a substitutional study with its antiferromagnetic analog MnPt5P. All compounds in the family adopt the layered anti-CeCoIn5-type structure with the space group P4/mmm, and EDS and x-ray diffraction results indicate that MnPt5P and MnPd5P form a complete solid solution. Based on measurements of the temperature-and field-dependent magnetization and resistance, we construct a temperature -composition (T -x) phase diagram for Mn(Pt1-xPdx )5P and demonstrate that the essentially antiferromagnetic order found in MnPt5P is extraordinarily sensitive to Pd substitution. At low Pd fractions (x 0.010, Mn(Pt1-xPdx )5P undergoes a only single transition into the ferromagnetic phase. The Curie temperature initially increases rapidly with x, rising from TC approximate to 197 K at x = 0.013 to a maximum of TC approximate to 312 K for x approximate to 0.62, and then falling back to TC approximate to 295 K for pure MnPd5P (x = 1.00). Given that Pt and Pd are isoelectronic, this work raises questions as to the origin of the extreme sensitivity of the magnetic ground state and the nature of the re-entrant ferromagnetism at dilute Pd levels.This article is published as Slade, Tyler J., Ranuri S. Dissanayaka Mudiyanselage, Nao Furukawa, Tanner R. Smith, Juan Schmidt, Lin-Lin Wang, Chang-Jong Kang et al. "Mn (Pt 1− x Pd x) 5 P: Isovalent tuning of Mn-sublattice magnetic order." Physical Review B 107, no. 13 (2023): 134429.
DOI: 10.1103/PhysRevB.107.134429.
Copyright 2023 American Physical Society.
Posted with permission.
DOE Contract Number(s): AC02-07CH11358; FOA-0001276; NSF-DMR-2053287; DMR-1644779; 2022R1C1C1008200