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1. Surface Segregation Across Ternary Alloy Composition Space: CuxAuyPd1−x−y

   https://doi.org/10.1021/acs.jpcc.0c02058  

   Yin, Chunrong; Guo, Zhitao; Gellman, Andrew (April 2020, Journal of physical chemistry)

   Surface segregation is a phenomenon common to all multicomponent materials and one that plays a critical role in determining their surface properties. Comprehensive studies of surface segregation versus bulk composition in ternary alloys have been prohibitive because of the need to study many different compositions. In this work, high-throughput low-energy He+ ionscattering spectra and energy-dispersive X-ray spectra were collected from a CuxAuyPd1−x−y composition spread alloy film under ultrahigh vacuum conditions. These have been used to quantify surface segregation across the entire CuxAuyPd1−x−y composition space (x = 0 → 1 and y = 0 → 1 − x). Surface compositions at 164 different bulk compositions were measured at 500 and 600 K. At both temperatures, Au shows the greatest tendency for segregation to the top-most surface while Pd is always depleted from the surface. Higher temperatures enhance the Au segregation. Segregation at most of the binary alloy bulk compositions matches with observations previously reported in the literature. However, surface compositions in the CuPd B2 composition region reveal segregation profiles that are nonmonotonic in bulk alloy composition. These were not observable in prior studies because of their limited resolution of composition space. An extended Langmuir−MacLean model, which describes ternary alloy segregation, has been used to analyze experimental data from the ternary alloys and to estimate pair-wise segregation free energies and segregation equilibrium constants. The ability to study surface segregation across the ternary alloy composition space with high-throughput methods has been validated, and the impact of bulk alloy phase on surface segregation is demonstrated and discussed. 

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2. Stability of magnetocaloric La(FexCoySi1-x-y)13 in water and air

   https://doi.org/10.1063/1.5080108  

   Javed, Khushar; Gupta, Shalabh; Pecharsky, Vitalij_K; Hadimani, Ravi_L (March 2019, AIP Advances)

   Stability of cobalt-doped lanthanum iron silicide, La(FexCoySi1-x-y)13 have been investigated under conditions required for magnetocaloric refrigeration. The XRD analysis revealed that both milled and non-milled samples stored in water loose a few Bragg peaks corresponding to the NaZn13 phase of La(FexCoySi1-x-y)13. Samples stored in air show well-defined Bragg peaks similar to that of pristine material. The SEM-EDS of the milled and non-milled samples stored in water and air show an increased concentration of oxygen in the samples, particularly those treated with water. The course non-milled powders stored in air and water show sharp transitions at the Curie temperature TC = 300K without large magnetization above the TC. The milled, fine-particulate sample stored in air shows a slightly broadened transition at TC, and that stored in deionized water for 14 days shows significantly broadened transition from 300K and retains large magnetizations above 400 K. This is indicative of relatively fast hydrolysis and removal of some or all of La, likely as hydroxide, from fine powders, leaving behind La-poor or, potentially, La-free Fe-Co-Si containing ferromagnetic residue with much higher Curie temperature. The non-milled course sample stored in water has sharper magnetic transition and higher magnetization hence it shows the highest entropy change among all 4 type of samples. 

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3. Wolfium bonds in homodimers of MX ₄ Y (M = Mo, W; X = F, Cl, Br; Y = O, S, Se)

   https://doi.org/10.1039/D3CP05867K  

   Michalczyk, Mariusz; Zierkiewicz, Wiktor; Scheiner, Steve (February 2024, Physical Chemistry Chemical Physics)

   The wolfium bond is a recently described noncovalent interaction in which metals belonging to group 6 act as electron acceptors. 

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4. Multicomponent Mechanochemical Synthesis of Cyclopentadienyl Titanium tert -Butoxy Halides, Cp _x TiX _y (O ^t Bu) _4–(x+y) ( x , y = 1, 2; X = Cl, Br)

   https://doi.org/10.1021/acsomega.8b00943  

   Boyde, Nicholas C.; Steelman, Grant W.; Hanusa, Timothy P. (July 2018, ACS Omega)
5. Exotic electronic structures of Sm _x Ce _3−x O _y (x = 0-3; y = 2-4) clusters and the effect of high neutral density of low-lying states on photodetachment transition intensities

   https://doi.org/10.1063/1.5043490  

   Topolski, Josey E.; Kafader, Jared O.; Marrero-Colon, Vicmarie; Iyengar, Srinivasan S.; Hratchian, Hrant P.; Jarrold, Caroline Chick (August 2018, The Journal of Chemical Physics)