More Like this

1. Prediction of a Non-Valence Temporary Anion State of (NaCl) ₂

   https://doi.org/10.1021/acs.jpcb.9b07782  

   Kairalapova, Arailym; Jordan, Kenneth D.; Falcetta, Michael F.; Steiner, Dalton K.; Sutter, Brittni L.; Gowen, Josiah S. (October 2019, The Journal of Physical Chemistry B)
2. Surface Valence State Effect of MoO _{2+ x} on Electrochemical Nitrogen Reduction

   https://doi.org/10.1002/advs.202104857  

   Wang, Jiaqi; Jiang, Zhou; Peng, Guiming; Hoenig, Eli; Yan, Gangbin; Wang, Mingzhan; Liu, Yuanyue; Du, Xiwen; Liu, Chong (April 2022, Advanced Science)
3. Pressure-induced shift of effective Ce valence, Fermi energy and phase boundaries in CeOs ₄ Sb ₁₂

   https://doi.org/10.1088/1367-2630/ac643c  

   Götze, K.; Pearce, M. J.; Coak, M. J.; Goddard, P. A.; Grockowiak, A. D.; Coniglio, W. A.; Tozer, S. W.; Graf, D. E.; Maple, M. B.; Ho, P-C; et al (April 2022, New Journal of Physics)

   Abstract CeOs₄Sb₁₂, a member of the skutterudite family, has an unusual semimetallic low-temperature $\mathcal{L}$-phase that inhabits a wedge-like area of the fieldH—temperatureTphase diagram. We have conducted measurements of electrical transport and megahertz conductivity on CeOs₄Sb₁₂single crystals under pressures of up to 3 GPa and in high magnetic fields of up to 41 T to investigate the influence of pressure on the differentH–Tphase boundaries. While the high-temperature valence transition between the metallic $\mathcal{H}$-phase and the $\mathcal{L}$-phase is shifted to higherTby pressures of the order of 1 GPa, we observed only a marginal suppression of the $\mathcal{S}$-phase that is found below 1 K for pressures of up to 1.91 GPa. High-field quantum oscillations have been observed for pressures up to 3.0 GPa and the Fermi surface of the high-field side of the $\mathcal{H}$-phase is found to show a surprising decrease in size with increasing pressure, implying a change in electronic structure rather than a mere contraction of lattice parameters. We evaluate the field-dependence of the effective masses for different pressures and also reflect on the sample dependence of some of the properties of CeOs₄Sb₁₂which appears to be limited to the low-field region. 

   more » « less
4. Strong enhancement of magnetic ordering temperature and structural/valence transitions in EuPd ₃ S ₄ under high pressure

   https://doi.org/10.1073/pnas.2310779120  

   Huyan, Shuyuan; Ryan, Dominic H.; Slade, Tyler J.; Lavina, Barbara; Jose, Greeshma; Wang, Haozhe; Wilde, John M.; Ribeiro, Raquel A.; Zhao, Jiyong; Xie, Weiwei; et al (December 2023, Proceedings of the National Academy of Sciences)

   We present a comprehensive study of the inhomogeneous mixed-valence compound, EuPd₃S₄, by electrical transport, X-ray diffraction, time-domain¹⁵¹Eu synchrotron Mössbauer spectroscopy, and X-ray absorption spectroscopy measurements under high pressure. Electrical transport measurements show that the antiferromagnetic ordering temperature,T_N, increases rapidly from 2.8 K at ambient pressure to 23.5 K at ~19 GPa and plateaus between ~19 and ~29 GPa after which no anomaly associated withT_Nis detected. A pressure-induced first-order structural transition from cubic to tetragonal is observed, with a rather broad coexistence region (~20 GPa to ~30 GPa) that corresponds to theT_Nplateau. Mössbauer spectroscopy measurements show a clear valence transition from approximately 50:50 Eu²⁺:Eu³⁺to fully Eu³⁺at ~28 GPa, consistent with the vanishing of the magnetic order at the same pressure. X-ray absorption data show a transition to a fully trivalent state at a similar pressure. Our results show that pressure first greatly enhancesT_N, most likely via enhanced hybridization between the Eu 4fstates and the conduction band, and then, second, causes a structural phase transition that coincides with the conversion of the europium to a fully trivalent state. 

   more » « less
5. New Photoelectron–Valence Electron Interactions Evident in the Photoelectron Spectrum of Gd ₂ O ^–

   https://doi.org/10.1021/acs.jpca.1c07818  

   Mason, Jarrett L.; Harb, Hassan; Abou Taka, Ali; Huizenga, Caleb D.; Corzo, Hector H.; Hratchian, Hrant P.; Jarrold, Caroline Chick (November 2021, The Journal of Physical Chemistry A)