  We report synthesis, structural details and electrical transport properties
of topological insulator Bi2Te3. The single crystalline specimens of Bi2Te3 are
obtained from high temperature (950C) melt and slow cooling (2C/hour). The
resultant crystals were shiny, one piece (few cm) and of bright silver color.
The Bi2Te3 crystal is found to be perfect with clear [00l] alignment. The
powder XRD pattern being carried out on crushed crystals showed that Bi2Te3
crystallized in R3m symmetry with a = b = 4.3866(2) A, c = 30.4978(13) A and
Gamma = 120degree. The Bi position is refined to (0, 0, 0.4038 (9)) at Wyckoff
position 6c and of Te are (0, 0, 0) at Wyckoff position 3a and at (0, 0,
0.2039(8)) at 6c. Ambient pressure and low temperature (down to 2K) electrical
transport measurements revealed metallic behavior. Magneto transport
measurements under magnetic field showed huge non saturating magneto resistance
(MR) reaching up to 250% at 2.5K and under 50KOe field. Summarily, the short
communication clearly demonstrates that Bi2Te3 topological insulator exhibit
non-saturating large positive MR at low temperature of say below 10K. The non
saturating MR is seen right up to room temperature albeit with much decreased
magnitude. Worth mentioning is the fact that these crystals are bulk in nature
and hence the anomalous MR is clearly an intrinsic property and not due to the
size effect as reported for nano-wires or thin films of the same.
