RATIONAL HOMOTOPY TYPE, RATIONAL PROPER HOMOTOPY TYPE AND RATIONAL PROPER HOMOTOPY TYPE AT INFINITY
Topology Proceedings. Vol. 37. 2011. P. 409-458
Ceramic solid solutions (Bi1-yLay)4(V 1-xMex)2O11-y with x, y < 0.2, Me-Zr, Ga, Fe, Cu, have been prepared by the solid state reaction method. Crystal structure parameters, phase transitions, dielectric and transport properties of ceramic samples have been studied. Concentration and temperature stability regions of monoclinic α-, orthorhombic β- and tetragonal γ- or γ'- polymorph modifications have been determined. Annealing of samples, containing large amount of Cu and/or La dopants, at 973 K in the reducing atmosphere resulted in their decomposition, though compositions containing low content of La, Ga or Zr dopants, remained pretty stable. © 2010 Elsevier B.V. All rights reserved.