SYNTHESIS AND PHYSICAL-PROPERTIES OF TL2BA2CUO6+DELTA SINGLE-CRYSTAL

Tl2Ba2CuO6+delta single crystals were prepared using a KCl flux method. Obtained crystals were thin plates grown in the a-b plane with a typical size of 2 x 2 x 0.01 mm3. The T(c) value was controlled from 0 K (nonsuperconducting normal metal) to 75 K by annealing in oxygen or argon atmosphere. The temperature dependence of the in-plane resistivity, rho(ab) changed from T2 to T1 with increasing T(c). The in-plane Hall coefficient R(H) was about +1 x 10(-3) cm3/C and exhibited a broad maximum at about 100 K. These results are very similar to those for ceramic samples. The resistivity along the c-axis, rho(c), showed metallic temperature dependence for all T(c)'s. The ratio of anisotropic resistivity (rho(c)/rho(ab)) measured by the Montgomery method was as large as 6 x 10(2) at room temperature even for a normal metallic sample.