采用濕化學方法制備了Co摻雜的二氧化錫納米粉(Sn1-xCoxO2)，經研究發現，Co以離子形式存在，而不是以單質形式存在，樣品中除了金紅石型的SnO2相之外，沒有發現其他雜質的相，隨著Co摻雜含量的增加，晶粒尺寸減小，光吸收譜紅移，禁帶寬度線性下降。鈷離子磁矩隨摻雜含量的增加而減小，這可能是由于占據晶格上近鄰陽離子位置的磁性離子數目增加使磁性離子成反鐵磁性排列的結果。Cobalt-doped SnO2 nano-powders (Sn1-xCoxO2) are fabricated by wet chemical method. It is found that cobalt exists as an ionic state instead of pure metal state. There is no other impurity phase in the samples except for rutile type SnO2. With the increase of cobalt concentration, the crystalline size decreases, the optical absorption spectra red-shiftes, and the band gap decreases linearly. The decrease of magnetic moment per cobalt atom with the increase of cobalt concentration could be attributed to the increased number of cobalt atoms occupying adjacent cation lattice positions that result in antiferromagnetic alignment.