Rethinking Antitrust Tools for Multi-Sided Platforms

Abstract

A microwave magnetic probe capable of measuring the spatial variation of the magnetic properties of materials has been developed. In contrast to other forms of microscopes, this instrument measures the spatial variation of the important magnetic properties of a sample directly by a selective microwave resonance technique. To date, we have observed clear resonances in portions of Permalloy films (∼1000 A thick) with a cross‐sectional diameter of 0.010 in. By using a cavity made of superconducting material, it is anticipated that resonances in spots as small as 200 A in cross‐sectional diameter may be observed. Some representative experimental results using this microscope are given to indicate its utility. © 1962 The American Institute of Physics