Below T(N) approximately 17 K the 29Si NMR line in URu2Si2 exhibits a previously unobserved field-independent nearly isotropic contribution to the linewidth, which increases to approximately 12 G as T-->0. We argue that this feature does not arise from static freezing of the U-spin magnetization, but is due to coupling between 29Si spins and a hidden order parameter. We discuss time-reversal symmetry-breaking orbital antiferromagnetism and indirect nuclear spin-spin interactions as possible coupling mechanisms. Further NMR experiments and theoretical calculations are suggested.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.87.196402 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Organic-Inorganic Hybrid Ladder-like Polysilsesquioxanes as Compatibilized Nanofiller for Nanocomposite Materials.
Molecules
December 2024
Aix Marseille Univ, CNRS, Chemistry Department, Institute of Radical Chemistry (ICR), 13397 Marseille, France.
Nanocomposite materials composed of an organic matrix and an inorganic nanofiller have been the subject of intense research in recent years. Indeed, the synergy between these two phases confers improved properties thanks to an increased surface-volume ratio, which reinforces the interactions between the particles and the polymer matrix. These interactions depend on many factors such as the shape, size and dispersion of the nanoobjects.
View Article and Find Full Text PDFMicrostructure and Bioactivity of Ca- and Mg-Modified Silicon Oxycarbide-Based Amorphous Ceramics.
Materials (Basel)
December 2024
National Key Laboratory of Science and Technology on High-Strength Structural Materials, Central South University, Changsha 410083, China.
Silicon oxycarbide (SiOC), Ca- and Mg-modified silicon oxycarbide (SiCaOC and SiMgOC) were synthesized via sol-gel processing with subsequent pyrolysis in an inert gas atmosphere. The physicochemical structures of the materials were characterized by XRD, SEM, FTIR, and Si MAS NMR. Biocompatibility and in vitro bioactivity were detected by MTT, cell adhesion assay, and simulated body fluid (SBF) immersion test.
View Article and Find Full Text PDFHomonuclear decoupled INADEQUATE NMR methods with improved sensitivity and resolution in solid-state NMR.
J Magn Reson
December 2024
Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181, UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France. Electronic address:
The two-dimensional (2D) refocused INADEQUATE NMR experiment, which correlates double-quantum (DQ) and single-quantum (SQ) coherences, is widely used to probe the chemical connectivities in solids. Nevertheless, the multiplets along the F dimension reduce the resolution and sensitivity of this experiment. The Composite-Refocusing (CR) technique with two excitation pulses has been proposed to suppress these multiplets in 2D INADEQUATE spectra of liquids.
View Article and Find Full Text PDFTriphenyl-Modified Mixed-Mode Stationary Phases With and Without Embedded Ion-Exchange Sites for High-Performance Liquid Chromatography.
J Sep Sci
December 2024
Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Tübingen, Germany.
The present work reports on the preparation, characterization, and evaluation of a set of novel triphenyl-modified silica-based stationary phases without and with embedded ion-exchange sites for mixed-mode liquid chromatography. The three synthesized triphenyl phases differed in additionally incorporated ion-exchange sites. In one embodiment, allyltriphenylsilane was bonded to thiol-modified silica by thiol-ene click reaction, leading to particles with no ion-exchange sites.
View Article and Find Full Text PDFSynthesis of Hollow Zn/ZSM-5 Nanosheets via Different Alkali Treatments with ZIF-8 as a Zn Source for Efficient Aromatization of Methanol.
Langmuir
December 2024
State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Diffusion limitations and monofunctional acidity of ZSM-5 molecular sieves affect the catalyst stability and aromatic yield in the reaction of methanol to aromatics (MTA). In this study, based on ZSM-5 nanosheets as parent molecular sieves, Zn-modified hollow ZSM-5 nanosheets were obtained after hydrothermal treatment by adding ZIF-8 or zinc nitrate as a source of Zn while treating with different types and concentrations of alkali solutions. The physical and chemical properties of the fabricated samples and their catalytic performance of methanol aromatization were systematically investigated by a combination of XRD, TEM, N adsorption-desorption, NH-TPD, Py-IR, Al MAS NMR, Si MAS NMR, XPS, and TG characterization analyses and MTA experimental evaluation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!