Tip for Spin-Polarized Tunneling
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Increasing demand for storage devices with higher packing densities requires the use of smaller domain structures than employed in the present-day hard disk and bubble domain type memories. A lateral resolution in the nanometer range permitting information to be obtained on the magnetic domains as well as on the domain walls, i.e., on the changes of magnetization in real space, is achieved with a technique which benefits from the characteristics of the scanning tunneling microscope (STM). The main difficulty in using a usual ferromagnetic tip is that the magnetism is mostly carried by d-electrons, whereas the more extended s-wave functions carry the tunnel current. However, the latter are expected to have energy splitting which is too small to give good magnetic resolution.