Floating zone growth and properties of La1-xAxMnO3 (A = Ca,Sr) single crystals

Single-crystal (La(1-x)A(x))(y)MnO3 (A = Sr, Ca; x = 0-0.3) boules without impurities and inclusions of other phases were produced by floating zone melting. The electron probe microanalyzer revealed a rather homogeneous Sr distribution but with a strong variation of Ca along the growth direction of the resulting boules. Concentration inhomogeneity of the Ca-doped single crystal can be significantly reduced by using the travelling solvent floating zone method (TSFZ) with the solvent enriched with Ca and Mn. TSFZ resulted in a decrease in the amplitude of the Ca concentration deviation in the (La1-x,Ca-x), MnO3 (x > 0.2) single crystals down to 10%. Penetration effects of liquid from the molten zone into the charge rod on the homogeneity of both Sr- and Ca-doped single crystals have been studied. (C) 2002 Elsevier Science B.V. All rights reserved.