Open AccessSelf-Propagating High-Temperature Synthesis of Chromium Substituted Lanthanide – Barium – Copper Oxides, LnBa2Cu3-xCrxO7-y (Ln = Y; La; Nd; Sm and Yb)
Author(s) -
М. В. Кузнецов,
Ivan P. Parkin,
Yu. G. Morozov,
А. Г. Мержанов
Publication year - 2017
Publication title -
eurasian chemico-technological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.227
H-Index - 9
eISSN - 2522-4867
pISSN - 1562-3920
DOI - 10.18321/ectj521
Subject(s) - chromium , orthorhombic crystal system , materials science , barium , nuclear chemistry , analytical chemistry (journal) , tetragonal crystal system , lanthanide , chemistry , crystallography , metallurgy , crystal structure , ion , organic chemistry , chromatography
A series of MBa 2 Cu 3-x CrxO 7-y (M = Y; La; Nd; Sm and Yb; x = 0, 0.05, 0.15, 0.25) materials were synthesized in air by self-propagating high-temperature synthesis (SHS) involving reaction of stoichiometric mixtures of rare-earth metal (III) oxide, barium peroxide, copper metal, chromium (III) oxide and sodium perchlorate. All the SHS processes were followed by sintering in oxygen at 950 °C for 2h. The products were characterized by SEM, X-ray powder diffraction, UV, superconductive transition temperatures (T c ) and magnetic susceptibility (χ) measurements. X-ray diffraction data showed that single phase orthorhombic (or tetragonal for M = Nd) materials were produced. All series of materials showed a systematic increase in lattice parameters and unit cell volume with chromium content (M = Y: x = 0, V = 174.25 Å3; x = 0.25, V = 175.10 Å3). Thermal stability of all the SHS prepared materials increased with x . Oxygen content of all the samples increased with x , but did not exceed 7.0. Superconductivity transition temperature decreased with chromium substitution in all systems (98-77 K). Magnetic susceptibility decreased with chromium substitution.