All-temperature barocaloric effects at pressure-induced phase transitions

Zhao, X.*; Zhang, Z.*; Hattori, Takanori; Wang, J.*; Li, L.*; Jia, Y.*; Li, W.*; Xue, J.*; Fan, X.*; Song, R.*; et al.

Nature Communications (Internet), 16, p.7713_1 - 7713_8, 2025/08

https://doi.org/10.1038/s41467-025-63068-z

Caloric effects usually occur in the vicinity of solid-state phase transitions with a limited refrigeration temperature span. Here, we introduce and realize an unprecedented concept -all temperature barocaloric effect, i.e., a remarkable barocaloric effect in KPF across an exceptionally wide temperature span, from 77.5 to 300 K and potentially down to 4 K, covering typical room temperature, liquid nitrogen, liquid hydrogen, and liquid helium refrigeration regions. The directly measured barocaloric adiabatic temperature change reaches 12 K at room temperature and 2.5 K at 77.5 K upon the release of a 250 MPa pressure. This effect is attributed to a persistent phase transition to a rhombohedral high pressure phases. We depict the thermodynamic energy landscape to account for the structural instability. This unique all-temperature barocaloric effect presents a novel approach to highly applicable solid-state refrigeration technology, transcending the conventional multi-stage scenario.

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.

Archie's cementation factors for natural rocks; Measurements and insights from diagenetic perspectives

Yuan, X.*; Hu, Q. H.*; Fang, X.*; Wang, Q. M.*; Ma, Y.*; Tachi, Yukio

Sedimentary Geology, 465, p.106633_1 - 106633_14, 2024/05

https://doi.org/10.1016/j.sedgeo.2024.106633

Extreme phonon anharmonicity underpins superionic diffusion and ultralow thermal conductivity in argyrodite AgSnSe

Ren, Q.*; Gupta, M. K.*; Jin, M.*; Ding, J.*; Wu, J.*; Chen, Z.*; Lin, S.*; Fabelo, O.*; Rodriguez-Velamazan, J. A.*; Kofu, Maiko; et al.

Nature Materials, 22(8), p.999 - 1006, 2023/08

https://doi.org/10.1038/s41563-023-01560-x

Pore connectivity influences mass transport in natural rocks; Pore structure, gas diffusion and batch sorption studies

Yuan, X.*; Hu, Q.*; Lin, X.*; Zhao, C.*; Wang, Q.*; Tachi, Yukio; Fukatsu, Yuta; Hamamoto, Shoichiro*; Siitari-Kauppi, M.*; Li, X.*

Journal of Hydrology, 618, p.129172_1 - 129172_15, 2023/03

https://doi.org/10.1016/j.jhydrol.2023.129172

Structure of an aqueous RbCl solution in the gigapascal pressure range by neutron diffraction combined with empirical potential structure refinement modeling

Zhang, W. Q.*; Yamaguchi, Toshio*; Fang, C. H.*; Yoshida, Koji*; Zhou, Y. Q.*; Zhu, F. Y.*; Machida, Shinichi*; Hattori, Takanori; Li, W.*

Journal of Molecular Liquids, 348, p.118080_1 - 118080_11, 2022/02

https://doi.org/10.1016/j.molliq.2021.118080

The ion hydration and association and hydrogen-bonded water structure in an aqueous 3 mol/kg RbCl solution were investigated at 298 K/0.1 MPa, 298 K/1 GPa, 523 K/1 GPa, and 523 K/4 GPa by neutron diffraction combined with EPSR methods. The second hydration layer of Rb and Cl becomes evident under elevated pressure and temperature conditions. The average oxygen coordination number of Rb (Cl) in the first hydration layer increases from 6.3 (5.9) ambient pressure to 8.9 (9.1) at 4 GPa, while decreasing coordination distance from 0.290 nm (0.322 nm) to 0.288 nm (0.314 nm). The orientation of the water dipole in the first solvation shell of Rb and a central water molecule is sensitive to pressure, but that in the first solvation shell of Cl does not change very much. The number of contact-ion pairs Rb-Cl decreases with elevated temperature and increases with elevated pressure. Water molecules are closely packed, and the tetrahedral hydrogen-bonded network of water molecules no longer exists in extreme conditions.

Suppressed lattice disorder for large emission enhancement and structural robustness in hybrid lead iodide perovskite discovered by high-pressure isotope effect

Kong, L.*; Gong, J.*; Hu, Q.*; Capitani, F.*; Celeste, A.*; Hattori, Takanori; Sano, Asami; Li, N.*; Yang, W.*; Liu, G.*; et al.

Advanced Functional Materials, 31(9), p.2009131_1 - 2009131_12, 2021/02

https://doi.org/10.1002/adfm.202009131

The soft nature of organic-inorganic halide perovskites renders their lattice particularly tunable to external stimuli such as pressure, undoubtedly offering an effective way to modify their structure for extraordinary optoelectronic properties. However, these soft materials meanwhile feature a general characteristic that even a very mild pressure will lead to detrimental lattice distortion and weaken the critical light-matter interaction, thereby triggering the performance degradation. Here, using the methylammonium lead iodide as a representative exploratory platform, we observed the pressure-driven lattice disorder can be significantly suppressed via hydrogen isotope effect, which is crucial for better optical and mechanical properties previously unattainable.

Port-based plasma diagnostic infrastructure on ITER

Pitcher, C. S.*; Barnsley, R.*; Bertalot, L.*; Encheva, A.*; Feder, R.*; Friconneau, J. P.*; Hu, Q.*; Levesy, B.*; Loesser, G. D.*; Lyublin, B.*; et al.

Fusion Science and Technology, 64(2), p.118 - 125, 2013/08

https://doi.org/10.13182/FST13-A18065

The port-based plasma diagnostic infrastructure on ITER is described, including the port plugs, the interspace support structure and port cell structure. These systems are modular in nature with standardized dimensions. The design of the equatorial and upper port plugs and their modules is discussed, as well as the dominant loading mechanisms. The port infrastructure design has now matured to the point that port plugs are now being populated with multiple diagnostics supplied by a number of ITER partners - two port plug examples are given.

Nuclear engineering of diagnostic port plugs on ITER

Pitcher, C. S.*; Barnsley, R.*; Feder, R.*; Hu, Q.*; Loesser, G. D.*; Lyublin, B.*; Padasalagi, S.*; Pak, S.*; Reichle, R.*; Sato, Kazuyoshi; et al.

Fusion Engineering and Design, 87(5-6), p.667 - 674, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.01.043

0.56 GeV laser electron acceleration in ablative-capillary-discharge plasma channel

Kameshima, Takashi; Hong, W.*; Sugiyama, Kiyohiro*; Wen, X.*; Wu, Y.*; Tang, C.*; Zhu, Q.*; Gu, Y.*; Zhang, B.*; Peng, H. S.*; et al.

Applied Physics Express, 1(6), p.066001_1 - 066001_3, 2008/05

https://doi.org/10.1143/APEX.1.066001

A high-quality electron beam with a central energy of 0.56 GeV, an energy spread of 1.2 % rms, and a divergence of 0.59 mrad rms was produced by means of a 4cm ablative-capillary-discharge plasma channel driven by a 3.8 J 27 fs laser pulse. This is the first demonstration of electron acceleration with an ablative capillary discharge where in the capillary is stably operated in vacuum with a simple system triggered by a laser pulse. This result of the generation of a high-quality beam provides the prospects to realize a practical accelerator based on laser-plasma acceleration.