Provided is a method for preparing non-magnetic nickel powders. The method include (a) heating a mixture including a nickel precursor compound and a polyol to reduce the nickel precursor compound to nickel powders with a face-centered cubic (FCC) crystal structure, and (b) heating the resultant mixture of step (a) to transform at least a portion of the nickel powders with the FCC crystal structure to nickel powders with a hexagonal close packed (HCP) crystal structure.