Growth and morphology of the single crystals of thermoelectric oxide material NaxCoO2

We have grown single crystals of recently discovered thermoelectric oxide material NaxCoO2 using NaCl flux. Crystals of sizes upto 1.5 x 1.5 x 1.5 mm3 having different morphological habits were reproducibly grown. The atomic force microscopic studies show that along c-axis crystals grow via 2D layer-by-layer mechanism. The X-ray diffraction analyses show that grown crystals are rich in Na content as compared to the starting charge indicating that NaCl flux also acts as a source of Na. The resistivity of the crystals exhibited a linear temperature dependence in the region between 30 and 300 K. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim