By using expansive and mobile properties of silicone oil, a characteristic wedge-shaped iron (Fe) film system with a slope of about 10(-5)rad has been prepared on glass substrates by a direct current magnetron sputtering method. Telephone cord buckles induced by residual compressive stress can be widely observed in the wedge-shaped films. The wavelength lambda and amplitude A of the wavy buckles increase linearly with the film thickness h, but the ratio of A to lambda (A/lambda) remains a constant of about 0.34. The atomic force microscopy cross-sections show that as the film thickness increases, the half buckle width b increases drastically whereas the maximum buckle deflection 6 is almost unchanged, and therefore the ratio of 6 to b (delta/b) decreases steadily. (C) 2009 Elsevier B.V. All rights reserved.