The Crystallographic Orientation Dependence of Snoek-Type Internal Friction Peaks of an Fe-Si Alloy

Abstract
Snoek-type internal friction peaks of a ternary alloy of iron, silicon and nitrogen were investigated with a special reference to the crystallographic orientation of applied stress. The two abnormal Snoek peaks discovered so far are found to have the same orientation dependence as the normal Snoek peak in alpha iron. From this fact and Nowick & Heller's “selection rule” (A. S. Nowick & W. R. Heller: Advances in Phys. 14 (1965) 101), it is concluded that the defects, jumps of which give rise to the abnormal Snoek peaks, must produce tetragonal or orthorhombic local strain around them. Two possible mechanisms of the abnormal Snoek peaks are proposed on the basis of this symmetry condition of the strain.