Abstract: Zn_1-xCr_xO diluted magnetic semiconductors were synthesized by hydrothermal method at 260℃ for about 28h with different concentrations of Cr (x=0.1, 0.15, 0.2 and 0.25), NaOH with concentration of 3mol/L were used as the mineralizer. X-ray diffraction patterns indicate
that as-prepared Cr-alloyed ZnO has the wurtzite structure with Zn²⁺ partially substituted by Cr₃₊ , and the average crystallite size of Zn_1-xCr_xO are 46.5, 46.1, 50.6 and 48.9nm, respectively. FE-SEM analyses show that the structure of nanopowders changes from short stylolitic structure to long stylolitic structrue when Cr concentration x increases to 0.2. The absorption peaks of Cr-doped nanopowders are demonstrated by UV-Vis analysis, and E_g of ZnO are 3.17, 3.18, 3.19 and 3.23eV, respectively. Room temperature VSM reveals a weakly paramagnetism behavior of the as-prepared Zn_1-xCr_xO nanocrystalline.

Key words: Zn_1-xCr_xO, diluted magnetic semiconductor, hydrothermal method, paramagnetism