Brightening triplet excitons enable high-performance white-light emission in organic small molecules via integrating n-- transitions

Yang, Q.*; Yang, X.*; Wang, Y.*; Fei, Y.*; Li, F.*; Zheng, H.*; Li, K.*; Han, Y.*; Hattori, Takanori; Zhu, P.*; et al.

Nature Communications (Internet), 15, p.7778_1 - 7778_9, 2024/09

https://doi.org/10.1038/s41467-024-52196-7

Luminescent materials that simultaneously embody bright singlet and triplet excitons hold great potential in optoelectronics, signage, and information encryption. However, achieving high-performance white-light emission is severely hampered by their inherent unbalanced contribution of fluorescence and phosphorescence. Herein, we address this challenge by pressure treatment engineering via hydrogen bonding cooperativity effect to realize the mixture of n-- transitions, where the triplet state emission was boosted from 7% to 40% in isophthalic acid (IPA). A superior white-light emission based on hybrid fluorescence and phosphorescence was harvested in pressure-treated IPA, and the photoluminescence quantum yield was increased to 75% from the initial 19% (blue-light emission). In-situ high-pressure IR spectra, X ray diffraction, and neutron diffraction reveal continuous strengthening of the hydrogen bonds with the increase of pressure. Furthermore, this enhanced hydrogen bond is retained down to the ambient conditions after pressure treatment, awarding the targeted IPA efficient intersystem crossing for balanced singlet/triplet excitons population and resulting in efficient white-light emission. This work not only proposes a route for brightening triplet states in organic small molecule, but also regulates the ratio of singlet and triplet excitons to construct high-performance white-light emission.

Low spin spectroscopy of neutron-rich Cl via and decay

Tripathi, V.*; Bhattacharya, S.*; Rubino, E.*; Benetti, C.*; Perello, J. F.*; Tabor, S. L.*; Liddick, S. N.*; Bender, P. C.*; Carpenter, M. P.*; Carroll, J. J.*; et al.

Physical Review C, 109(4), p.044320_1 - 044320_15, 2024/04

https://doi.org/10.1103/PhysRevC.109.044320

no abstracts in English

decay of exotic P and S isotopes with neutron number near 28

Tripathi, V.*; Bhattacharya, S.*; Rubino, E.*; Benetti, C.*; Perello, J. F.*; Tabor, S. L.*; Liddick, S. N.*; Bender, P. C.*; Carpenter, M. P.*; Carroll, J. J.*; et al.

Physical Review C, 106(6), p.064314_1 - 064314_14, 2022/12

https://doi.org/10.1103/PhysRevC.106.064314

no abstracts in English

Nanoscale heterogeneity induced by nonmagnetic Zn dopants in the quantum critical metal CeCoIn; In NQR/NMR and Co NMR study

Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Zhu, J.-X.*; Ronning, F.*; Thompson, J. D.*; Ramakrishna, S. K.*; Reyes, A. P.*; Suzuki, Kohei*; Oshima, Yoshiki*; et al.

Physical Review B, 104(8), p.085106_1 - 085106_12, 2021/08

https://doi.org/10.1103/PhysRevB.104.085106

Antiferromagnetism in a prototypical quantum critical metal CeCoIn is known to be induced by slight substitutions of non-magnetic Zn atoms for In. In nominally 7% Zn substituted CeCoIn, an antiferromagnetic (AFM) state coexists with heavy fermion superconductivity. Heterogeneity of the electronic states is investigated in Zn doped CeCoIn by means of nuclear quadrupole and magnetic resonances (NQR and NMR). Site-dependent NQR relaxation rates indicate that the AFM state is locally nucleated around Zn substituents in the matrix of a heavy fermion state, and percolates through the bulk at the AFM transition temperature . At lower temperatures, an anisotropic superconducting (SC) gap below the SC transition temperature , and the SC state permeates through the AFM regions via a SC proximity effect. Applying an external magnetic field induces a spin-flop transition near 5 T, reducing the volume of the AFM regions. Consequently, a short ranged inhomogeneous AFM state survives and coexists with a paramagnetic Fermi liquid state at high fields.

Stability and synthesis of superheavy elements; Fighting the battle against fission - Example of No

Lopez-Martens, A.*; Henning, G.*; Khoo, T. L.*; Seweryniak, D.*; Alcorta, M.*; Asai, Masato; Back, B. B.*; Bertone, P. F.*; Boilley, D.*; Carpenter, M. P.*; et al.

EPJ Web of Conferences, 131, p.03001_1 - 03001_6, 2016/12

https://doi.org/10.1051/epjconf/201613103001

Fission barrier height and its angular-momentum dependence have been measured for the first time in the nucleus with the atomic number greater than 100. The entry distribution method, which can determine the excitation energy at which fission starts to dominate the decay process, was applied to No. The fission barrier of No was found to be 6.6 MeV at zero spin, indicating that the No is strongly stabilized by the nuclear shell effects.

Carrier-mediated ferromagnetism in the magnetic topological insulator Cr-doped (Sb,Bi)Te

Ye, M.*; Li, W.*; Zhu, S.-Y.*; Takeda, Yukiharu; Saito, Yuji; Wang, J.*; Pan, H.*; Nurmamat, M.*; Sumida, Kazuki*; Ji, F.*; et al.

Nature Communications (Internet), 6, p.8913_1 - 8913_7, 2015/11

AA2015-0647.pdf:0.64MB

https://doi.org/10.1038/ncomms9913

Magnetically doped topological insulators are predicted to exhibit exotic phenomena including the quantized anomalous Hall effect and a dissipationless transport, which facilitate the development of low-power-consumption devices using electron spins. The realization of the quantized anomalous Hall effect is so far restricted to the Cr-doped (Sb,Bi)Te system at extremely low temperature; however, the microscopic origin of its ferromagnetism is poorly understood. Here we present an element-resolved study for Cr-doped (Sb,Bi)Te using X-ray magnetic circular dichroism to unambiguously show that the long-range magnetic order is mediated by the p-hole carriers of the host lattice, and the interaction between the Sb(Te) p and Cr d states is crucial.

Fission barrier of superheavy nuclei and persistence of shell effects at high spin; Cases of No and Th

Henning, G.*; Khoo, T. L.*; Lopez-Martens, A.*; Seweryniak, D.*; Alcorta, M.*; Asai, Masato; Back, B. B.*; Bertone, P. F.*; Boilley, D.*; Carpenter, M. P.*; et al.

Physical Review Letters, 113(26), p.262505_1 - 262505_6, 2014/12

https://doi.org/10.1103/PhysRevLett.113.262505

Fission barrier heights of a shell-stabilized superheavy nucleus No have been determined as a function of spin up to 19 through the measured distribution of entry points of deexcitations in the excitation energy vs. spin plane. The fission barrier height of No was determined to be 6.0 MeV at spin 15, and 6.6 MeV at spin 0 by extrapolation. This demonstrates that the shell effect actually enlarges the fission barrier in such heavy nuclei and keeps the barrier high even at high spin.

Evidence for rigid triaxial deformation at low energy in Ge

Toh, Yosuke; Chiara, C. J.*; McCutchan, E. A.*; Walters, W. B.*; Janssens, R. V. F.*; Carpenter, M. P.*; Zhu, S.*; Broda, R.*; Fornal, B.*; Kay, B. P.*; et al.

Physical Review C, 87(4), p.041304_1 - 041304_5, 2013/04

https://doi.org/10.1103/PhysRevC.87.041304

Excited states of Ge have been investigated via the Ge + U reaction with Ge MeV by use of in-beam -ray spectroscopy using the sphere array. The band was extended considerably and one new band was identified. Comparisons of the band with collective- and shell-model calculations suggest that Ge may be a rare example of a nucleus exhibiting rigid triaxial deformation in the low-lying states.

ITER test blanket module error field simulation experiments at DIII-D

Schaffer, M. J.*; Snipes, J. A.*; Gohil, P.*; de Vries, P.*; Evans, T. E.*; Fenstermacher, M. E.*; Gao, X.*; Garofalo, A. M.*; Gates, D. A.*; Greenfield, C. M.*; et al.

Nuclear Fusion, 51(10), p.103028_1 - 103028_11, 2011/10

https://doi.org/10.1088/0029-5515/51/10/103028

Experiments at DIII-D investigated the effects of ferromagnetic error fields similar to those expected from proposed ITER Test Blanket Modules (TBMs). Studied were effects on: plasma rotation and locking; confinement; L-H transition; edge localized mode (ELM) suppression by resonant magnetic perturbations; ELMs and the H-mode pedestal; energetic particle losses; and more. The experiments used a 3-coil mock-up of 2 magnetized ITER TBMs in one ITER equatorial port. The experiments did not reveal any effect likely to preclude ITER operations with a TBM-like error field. The largest effect was slowed plasma toroidal rotation v across the entire radial profile by as much as via non-resonant braking. Changes to global , and were 3 times smaller. These effects are stronger at higher and lower . Other effects were smaller.

Search for a 2-quasiparticle high- isomer in Rf

Robinson, A. P.*; Khoo, T. L.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; Davids, C. N.*; Greene, J.*; et al.

Physical Review C, 83(6), p.064311_1 - 064311_7, 2011/06

https://doi.org/10.1103/PhysRevC.83.064311

We have identified an isomer with a half-life of 17 s in Rf through a calorimetric conversion electron measurement tagged with implanted Rf nuclei using the fragment mass analyzer at Argonne National Laboratory. The low population yield for this isomer suggests that this isomer should not be a 2-quasiparticle high- isomer which is typically observed in the N = 152 isotones, but should be a 4-quasiparticle one. Possible reasons of the non-observation of a 2-quasiparticle isomer are this isomer decays by fission with a half-life similar to that of the ground state of Rf. Another possibility, that there is no 2-quasiparticle isomer at all, would imply an abrupt termination of axially symmetric deformed shape at Z=104.