GOALI: Magnetic Microstructure and Information Storage

Washington University, Saint Louis MO

Investigators

Abstract

MAGNETIC MICROSTRUCTURE AND INFORMATION STORAGE Abstract This research project addresses the challenges facing the magnetic storage industry as storage densities approach the superparamagnetic limit. It is designed to contribute to the long-term basis of the technology in a form that will be useful to the practitioners in industry. Storage density and stability are related to the magnetic microstructure of storage media. A useful microstructural magnetic unit of a storage medium is the smallest piece of the medium whose magnetization can be altered, and which will reliably retain its altered state for a specified length of time. Each stored bit in virtually all existing magnetic storage systems comprises a large but shrinking number of microstructural magnetic units, and in all practical and economically viable systems the microstructural units have widely varying characteristics (particle, grain, or cluster size, orientation, etc.). We will apply innovative atomic and magnetic force microscopic (AFM and MFM) techniques that we have developed to measure the characteristics of the micromagnetic unit in a given medium, and modeling techniques that enable us to infer them indirectly. We propose to develop a carbon nanotube AFM/MFM tip that will give finer resolution to the measurements, and we will extend their scope to unconventional (perpendicular and patterned media) storage. In the storage medium environment, the stored bit is subjected to forces that shorten its thermal decay lifetime. We will combine our previously reported spin stand quantification of the effect of temperature and storage density on stability of written information with MFM measurements to measure thermal effects on the write process and medium noise.