Abstract: Precursors were synthesized by solid state reaction of zinc acetate with oxalic acid. ZnO gas sensing materials were obtained by decomposition of the precursors and characterized
by XRD and TEM. La₂O₃ and Nd₂O₃ were doped in nanometre ZnO materials by the methods of solid state and liquid state reaction. The sensitivity
of the materials was measured at various mole ratios of ZnO to La₂O₃ or Nd₂O₃. The gas sensitivity of ZnO element to C₂H₅OH,
NH₃ and LPG were measured in static state at a various operational temperatures. The results show that ZnO prepared by this method is highly sensitive to
C₂H₅OH and selective between C₂H₅OH, NH₃ and LPG at a low operational temperature.

Key words: nanometer, zinc oxide, solid sate synthesis, gas sensing properties