K. B. Kalmykov

Surface state of sacrificial copper electrode by electropolishing in hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.

Anodic dissolution of natural surface-oxidized, air-annealed, cathodically reduced, and cathodically deposited copper in hydrophobic ionic liquid 1-buthyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide under galvanostatic conditions by means of gravimetric measurements was studied. The resulting samples were mirror-like oxide-free copper pattern. The mechanism of the electropolishing of oxidized copper surface was considered. The consequent anodic reactions Cu2O - 1e = Cu(+) + CuO, CuO - 2e = Cu(2+) + O, and Cu - 1e = Cu(+) take place. The electropolishing itself occurs over oxygen-free copper surface due to competitive residual water discharge in the pits and copper dissolution on the roughness.

Crystal structure and phase transitions of ternary compounds in the thulium–silver–tin system

The existence of the TmAgSn compound in the Tm–Ag–Sn system in the form of two polymorphs was confirmed. The high-temperature phase crystallizes with the LiGaGe type (P63mc, Z = 2), and the lowtemperature one with the ZrNiAl type (

Phase equilibria in Cu-Al-Zr system at 1073 K and aluminum concentration of less than 55 at %

P\overline 6 2m

Study of the interaction of Pt and Rh with Nb or Ta

, Z = 3). A new ternary compound TmAgSn2 was found to exist (Cu3Au type,

Formation of a regular cellular structure on the surface of Zr67Ni30Si3 alloy at electrochemical polishing in ionic liquids

Pm\overline 3 m

Phase equilibria in the Al-Cu-Fe system at a temperature of 853 K in the aluminum enriched region

, Z = 1). The polymorphic transition temperature of the TmAgSn was found to be 1214 K using differential thermal analysis. A comparative investigation of the compounds by 119Sn Mössbauer spectroscopy showed a difference in the chemical bonding character of tin atoms: in TmAgSn2, tin has a typical valence state for metallic systems, whereas in both TmAgSn polymorphs additional interaction between the 5s orbitals of silver atoms and the 5p orbitals of tin atoms takes place.