By investigating the thermal variations of electrical resistance of a range of NixAl1-x sputter-deposited films, where x = 0.5-1, it was found that a thermally-activated transition from the insulator to metal state on increasing temperature occurred only within a narrow range of x from 0.75 to 0.8. At all other values of x investigated, the conduction behavior of the films appeared to be metallic as expected. The same observations were made on two different sputtering systems with different deposition conditions, indicating that the electrical transition from x = 0.75 to 0.8 is a highly reproducible phenomenon. (C) 2003 Elsevier B.V. All rights reserved.