Temperature-dependent hardening contributions in CrFeCoNi high-entropy alloy

Naeem, M.*; He, H.*; Harjo, S.; Kawasaki, Takuro; Lin, W.*; Kai, J.-J.*; Wu, Z.*; Lan, S.*; Wang, X.-L.*

Acta Materialia, 221, p.117371_1 - 117371_18, 2021/12

https://doi.org/10.1016/j.actamat.2021.117371

Phase transition and chemical reactivity of 1H-tetrazole under high pressure up to 100 GPa

Gao, D.*; Tang, X.*; Wang, X.*; Yang, X.*; Zhang, P.*; Che, G.*; Han, J.*; Hattori, Takanori; Wang, Y.*; Dong, X.*; et al.

Physical Chemistry Chemical Physics, 23(35), p.19503 - 19510, 2021/09

https://doi.org/10.1039/D1CP02913D

Pressure-induced phase transition and polymerization of nitrogen-rich molecules are widely focused due to its extreme importance for the development of green high energy density materials. Here, we present a study of the phase transition and chemical reaction of 1H-tetrazole up to 100 GPa by using Raman, IR, X-ray diffraction, neutron diffraction techniques and theoretical calculation. A phase transition above 2.6 GPa was identified and the high-pressure structure was determined with one molecule in a unit cell. The 1H-tetrazole polymerizes reversibly below 100 GPa, probably through a carbon-nitrogen bonding instead of nitrogen-nitrogen bonding. Our studies updated the structure model of the high pressure phase of 1H-tetrazole, and presented the possible intermolecular bonding route for the first time, which gives new insights to understand the phase transition and chemical reaction of nitrogen-rich compounds, and benefit for designing new high energy density materials.

Stacking fault driven phase transformation in CrCoNi medium entropy alloy

He, H.*; Naeem, M.*; Zhang, F.*; Zhao, Y.*; Harjo, S.; Kawasaki, Takuro; Wang, B.*; Wu, X.*; Lan, S.*; Wu, Z.*; et al.

Nano Letters, 21(3), p.1419 - 1426, 2021/02

https://doi.org/10.1021/acs.nanolett.0c04244

Formation and mobility of soil organic carbon in a buried humic horizon of a volcanic ash soil

Wijesinghe, J. N.*; Koarashi, Jun; Atarashi-Andoh, Mariko; Kokubu, Yoko; Yamaguchi, Noriko*; Sase, Takashi*; Hosono, Mamoru*; Inoue, Yuzuru*; Mori, Yuki*; Hiradate, Shuntaro*

Geoderma, 374, p.114417_1 - 114417_10, 2020/09

https://doi.org/10.1016/j.geoderma.2020.114417

Comparison of dislocation density, twin fault probability, and stacking fault energy between CrCoNi and CrCoNiFe medium entropy alloys deformed at 293 and 140K

Woo, W.*; Naeem, M.*; Jeong, J.-S.*; Lee, C.-M.*; Harjo, S.; Kawasaki, Takuro; He, H.*; Wang, X.-L.*

Materials Science & Engineering A, 781, p.139224_1 - 139224_7, 2020/04

https://doi.org/10.1016/j.msea.2020.139224

Ultralow thermal conductivity from transverse acoustic phonon suppression in distorted crystalline -MgAgSb

Li, X.*; Liu, P.-F.*; Zhao, E.*; Zhang, Z.*; Guide, T.*; Le, M. D.*; Avdeev, M.*; Ikeda, Kazutaka*; Otomo, Toshiya*; Kofu, Maiko; et al.

Nature Communications (Internet), 11(1), p.942_1 - 942_9, 2020/02

https://doi.org/10.1038/s41467-020-14772-5

In high-performance thermoelectric materials, there are two main low thermal conductivity mechanisms: the phonon anharmonic and phonon scattering resulting from the dynamic disorder, which have been successfully revealed by inelastic neutron scattering. Using neutron scattering and ab initio calculations, we report here a mechanism of static local structure distortion combined with phonon-anharmonic-induced ultralow lattice thermal conductivity in -MgAgSb. Since the transverse acoustic phonons are almost fully scattered by the intrinsic distorted rocksalt sublattice in this compound, the heat is mainly transported by the longitudinal acoustic phonons. The ultralow thermal conductivity in -MgAgSb is attributed to its atomic dynamics being altered by the structure distortion, which presents a possible microscopic route to enhance the performance of similar thermoelectric materials.

In-source laser spectroscopy of dysprosium isotopes at the ISOLDE-RILIS

Chrysalidis, K.*; Barzakh, A. E.*; Ahmed, R.*; Andreyev, A. N.; Ballof, J.*; Cubiss, J. G.*; Fedorov, D. V.*; Fedosseev, V. N.*; Fraile, L. M.*; Harding, R. D.*; et al.

Nuclear Instruments and Methods in Physics Research B, 463, p.472 - 475, 2020/01

https://doi.org/10.1016/j.nimb.2019.04.021

A number of radiogenically produced dysprosium isotopes have been studied by in-source laser spectroscopy at ISOLDE using the Resonance Ionization Laser Ion Source (RILIS). Isotope shifts were measured relative to Dy in the (gs) (418.8 nm )resonance transition. The electronic factor, , and mass shift factor, M, were extracted and used for determining the changes in mean-squared charge radii for Dy and Dy for the first time.

-decay branching ratio of Pt

Cubiss, J. G.*; Harding, R. D.*; Andreyev, A. N.; Althubiti, N.*; Andel, B.*; Antalic, S.*; Barzakh, A. E.*; Cocolios, T. E.*; Day Goodacre, T.*; Farooq-Smith, G. J.*; et al.

Physical Review C, 101(1), p.014314_1 - 014314_4, 2020/01

https://doi.org/10.1103/PhysRevC.101.014314

The -decay branching ratio of 0.52(5)% from the ground state of Pt to the ground state of the daughter nucleus Os has been determined more precisely than before. The Pt was produced as the -decay granddaughter of Hg which was produced and separated with the CERN-ISOLDE facility. The reduced -decay width calculated with the present result has provided a new picture of the systematics for the -decay width of neutron-deficient Pt isotopes.

Study of medium-spin states of neutron-rich Rb isotopes

Torres, D. A.*; Chapman, R.*; Kumar, V.*; Hadinia, B.*; Hodsdon, A.*; Labiche, M.*; Liang, X.*; O'Donnell, D.*; Ollier, J.*; Orlandi, R.; et al.

European Physical Journal A, 55(9), p.158_1 - 158_21, 2019/09

https://doi.org/10.1140/epja/i2019-12839-6

Fine structure in the decay of At

Cubiss, J. G.*; Andreyev, A. N.; Barzakh, A. E.*; Andel, B.*; Antalic, S.*; Cocolios, T. E.*; Day Goodacre, T.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; et al.

Physical Review C, 99(6), p.064317_1 - 064317_6, 2019/06

https://doi.org/10.1103/PhysRevC.99.064317

An decay of At was studied at the CERN-ISOLDE facility using a laser-ionization technique. Coincidence - data were collected for the first time and a more precise half-life value of T = 1.27(6) s was measured. A new -decay scheme was deduced based on the fine-structure of the decay. The results lead to a preferred spin and parity assignment of J = (3) for the ground state of At; however, J = (2) cannot be fully excluded.