Growth and investigation of doped rare earth manganite single crystals

When growing (La(1-x)A(x))(y)MnO3 (A = Sr, Ca; x = 0-0.3) single crystals b y floating zone melting for colossal magnetoresistive effect investigation it was observed that crystallisation nature depends on y = (La + A)/Mn rati o in a melt. Stable growth of undoped, Sr substituted (up to x = 0.3) and C a substituted (x < 0.1) single crystals takes place in air when y = 0.9-0.9 5. In the case of high rate of Ca substitution (x = 0.2-0.3) stable growth was observed only in oxygen reduced atmosphere. Single crystals of these co mpounds with mosaicity not more than 0.5 degrees were produced. Electrical and magnetic properties of as-grown and heat-treated samples were studied. (C) 1999 Elsevier Science B.V. All rights reserved.