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1. Synthesis, Crystal and Electronic Structures, and Magnetic and Electrical Transport Properties of Bismuthides NdZn _0.6 Bi ₂ and (La _0.5 RE _0.5 )Zn _0.6 Bi ₂ (RE = Pr or Nd)

   Prasad, Karishma; Upreti, Dinesh; Un_Nabi, Md Rafique; Oppong, Richeal A; Wang, Fei; Shinde, Manish; Hu, Jin; Wang, Jian (October 2024, Inorganic Chemistry)
2. 2D Homologous Series SrFM _n BiS _n+2 (M = Pb, Ag _0.5 Bi _0.5 ; n = 0, 1) and Commensurately Modulated Sr ₂ F ₂ Bi _2/3 S ₂

   https://doi.org/10.1021/acs.inorgchem.2c00663  

   Chen, Haijie; McClain, Rebecca; Shen, Jiahong; He, Jiangang; Malliakas, Christos D.; Spanopoulos, Ioannis; Zhang, Chi; Zhao, Chendong; Wang, Yang; Li, Qiang; et al (May 2022, Inorganic Chemistry)
3. High performance, electroforming-free, thin film memristors using ionic Na _0.5 Bi _0.5 TiO ₃

   https://doi.org/10.1039/D1TC00202C  

   Yun, Chao; Webb, Matthew; Li, Weiwei; Wu, Rui; Xiao, Ming; Hellenbrand, Markus; Kursumovic, Ahmed; Dou, Hongyi; Gao, Xingyao; Dhole, Samyak; et al (April 2021, Journal of Materials Chemistry C)

   null (Ed.)

   Here, in ionically conducting Na 0.5 Bi 0.5 TiO 3 (NBT), we explore the link between growth parameters, stoichiometry and resistive switching behavior and show NBT to be a highly tunable system. We show that the combination of oxygen ionic vacancies and low-level electronic conduction is important for controlling Schottky barrier interfacial switching. We achieve a large ON/OFF ratio for high resistance/low resistance ( R HRS / R LRS ), enabled by an almost constant R HRS of ∼10 9 Ω, and composition-tunable R LRS value modulated by growth temperature. R HRS / R LRS ratios of up to 10 4 and pronounced resistive switching at low voltages (SET voltage of <1.2 V without high-voltage electroforming), strong endurance (no change in resistance states after several 10 3 cycles), uniformity, stable switching and fast switching speed are achieved. Of particular interest is that the best performance is achieved at the lowest growth temperature studied (600 °C), which is opposite to the case of most other perovskite oxides for memristors, where higher growth temperatures are required for optimum performance. This is understood based on the oxygen vacancy control of interfacial switching in NBT, whereas a range of other mechanisms (including filamentary switching) occur in other perovskites. The study of NBT has enabled us to determine key parameters for achieving high performance memristors. 

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4. Thermally driven mesoscale chemomechanical interplay in Li _0.5 Ni _0.6 Mn _0.2 Co _0.2 O ₂ cathode materials

   https://doi.org/10.1039/C8TA08973F  

   Wei, Chenxi; Zhang, Yan; Lee, Sang-Jun; Mu, Linqin; Liu, Jin; Wang, Chenxu; Yang, Yang; Doeff, Marca; Pianetta, Piero; Nordlund, Dennis; et al (November 2018, Journal of Materials Chemistry A)

   While Li ion batteries are intended to be operated within a mild temperature window, their structural and chemical complexity could lead to unanticipated local electrochemical events that could cause extreme temperature spikes, which, in turn, could trigger more undesired and sophisticated reactions in the system. Visualizing and understanding the response of battery electrode materials to thermal abuse conditions could potentially offer a knowledge basis for the prevention and mitigation of the safety hazards. Here we show a comprehensive investigation of thermally driven chemomechanical interplay in a Li 0.5 Ni 0.6 Mn 0.2 Co 0.2 O 2 (charged NMC622) cathode material. We report that, at the early stage of the thermal abuse, oxygen release and internal Li migration occur concurrently, and are accompanied by mechanical disintegration at the mesoscale. At the later stage, Li protrusions are observed on the secondary particle surface due to the limited lithium solubility in non-layered lattices. The extraction of both oxygen and lithium from the host material at elevated temperature could influence the chemistry and safety at the cell level via rearrangement of the electron and ion diffusion pathways, reduction of the coulombic efficiency, and/or causing an internal short circuit that could provoke a thermal runaway. 

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5. Special quasirandom structures description of the local structure of disordered Bi _0.5 K _0.5 TiO ₃

   https://doi.org/10.1063/5.0123468  

   Jiang, Bo; Lin, De-Ye; Wang, Xin; Selbach, Sverre M.; Page, Katharine (December 2022, Journal of Applied Physics)

   Polar nanoregions (PNRs) are believed to play a decisive role in the local and macroscopic polarization in relaxor ferroelectrics. The limited microscopic understanding of the structure and dynamics of PNRs hampers the rational design of new lead-free materials. Here, the local structure of A-site disordered Bi 0.5 K 0.5 TiO 3 (BKT) is investigated using synchrotron x-ray and neutron pair distribution function (PDF) analysis and density functional theory (DFT) optimized special quasirandom structures (SQSs). DFT-relaxed SQS with a 4 × 4 × 4 supercell size can reproduce the experimental PDFs of disordered BKT, as well as the partial PDFs and total polarization, with comparable results to those reported from a combined analysis of x-ray and neutron PDF data with large-box reverse Monte Carlo methods. We find that small Bi 3+ -rich polar clusters are likely to be the microscopic origin of relaxor behavior in disordered BKT, and that the existence of large polar nanoregions (PNRs) is not necessary to explain the relaxor properties. Our results also highlight the great potential of the SQS approach to gain a nanoscale-to-microscopic understanding of other relaxor solid solutions. 

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