Growth and characterization of bulk Nd 2- xCe xCuO 4 single crystals

By using the modified Top Seeded Solution Growth technique high quality Nd _{2- x}Ce _xCuO ₄ single crystals with homogeneous cerium distribution and sizes up to 10×10×2 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°C, 15 for 1115°C and 5 for 1150°C. It was found that Pt dissolves in NCCO single crystals and completely suppresses superconductivity at the concentration 0.02 at./f.u. Although Nd _1.82Ce _0.18Cu _0.98Zr _0.02O _y and Nd _1.87Ce _0.13CuO _y single crystals obtained by the slow cooling method in YSZ and Al ₂O ₃ 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.