Growth and characterization of bulk Nd2-xCexCuO4 single crystals

By using the modified Top Seeded Solution Growth technique high quality Nd2-xCexCuO4 single crystals with homogeneous cerium distribution and sizes up to 10 X 10 X 2 mm have been prepared in Pt crucibles. It was revealed that the anisotropy of the growth rates in (001) plane and in [001] direction depends from growth temperature and equals 70 for 1050 degrees C, 15 for 1115 degrees C and 5 for 1150 degrees C. It was found that Pt dissolves in NCCO single crystals and completely suppresses superconductivity at the concentration 0.02 at./f.u. Although Nd1.82Ce0.18Cu0.98Zr0.02Oy and Nd1.87Ce0.13CuOy single crystals obtained by the slow cooling method in YSZ and Al2O3 crucibles demonstrate the superconductivity transitions with T-c = 20 K and T-c = 22 K but it was shown that ceramic crucibles are not stable and completely corroded within several days. The Borrmann effect was observed on the explored crystals. (C) 2000 Elsevier Science B.V. All rights reserved.