George C.G. The Magnetostriction of Specimens of Nickel and Invar as a Function of Tension

A Thesis Submitted for the Degree of Bachelor of Philosophy, Normal Course. University of Wisconsin, 1922. 38 p.Several investigators have made careful measurements of the elongation of various metals due to the magnetic fields in which they were placed. The alteration of the dimensions of a body due to magnetization is called magnetostriction. This paper is the result of observations of the magneto striction of a specimen of pure nickel and a specimen of invar.The question of magneto striction in reversible nickel steels is important in the construction of scales of extreme accuracy and in instruments where measurements must be exceedingly accurate for considerable load. Even the field of the earth makes a slight change in the dimensions of a metal holding up a load. The chief alteration of dimensions, however, is the one due to the magneto strictive effect caused by temperature variations, this being larger, but not to be confused with thermal expansion.