The objective of this research is to develop the basic technology and demonstrate the feasibility of a novel solid state magnetic memory in which the storage and retrieval of data is accomplished by surface acoustic waves. The approach is to use a phased array of interdigitated transducers to excite, steer and focus the surface acoustic waves on a contiguous magnetostrictive thin film for reading or writing data. E and inverse magnetostrictive effects are exploited respectively for reading and writing.
Intellectual Merit: The experiments proposed herein will be a first undertaking to demonstrate the inverse magnetostrictive effect due to surface acoustic waves. Additionally, the investigation of the interaction between high frequency surface acoustic waves and magnetostrictive materials will provide seminal understanding of the physics of magneto-mechanical coupling.
Broader Impact: Key advantages of the proposed memory device arise from its radiation hardness, mechanical robustness (no moving components) and likely lower cost than existing solid state memory technologies. It is envisaged for integration with products in portable consumer electronic and space applications. It is expected that the results from this project will forge a new area of research on magnetic surface acoustic wave devices. Potential applications for these devices will include sensors, tunable filters and 2-D associative memory. The project will train graduate and undergraduate students in subjects encompassing diverse engineering disciplines. The learning from the proposed work will be assimilated into the engineering curriculum, and disseminated through publications and presentations. The proposed educational outreach effort involves high school female students and K-12 teachers.
Intellectual Merit This research has demonstrated the feasibility of a new means of information storage, opening the path for a durable and inexpensive memory device that could one day find application in the multitude of electronic gadgets pervading our lives. This new storage technology called acoustically assisted magnetic recording (or, AAMR) relies on "magnetically softening" a hard magnetic film using strain generated by high frequency sound waves. The "softening" is temporary and local, allowing for the information bit to be easily recorded on the film. A press release related to this invention may be found at: http://oregonstate.edu/ua/ncs/archives/2013/feb/researchers-invent-"acoustic-assisted"-magnetic-information-storage Fundamentally, this research explored the interaction between phonons and magnons, which are a quantum physics description of sound and magnetization respectively. This is a rich and emerging area not only for sensors and data storage as demonstrated by this research but also for spin-caloritronics where an understanding of magnon-phonon interaction may lead to the development of thin film coatings that can convert waste heat into useable electrical energy. Broader Impact This award was instrumental in enabling a strong foundation for the nascent Applied Magnetics Research Laboratory at Oregon State University. The laboratory is now equipped with custom magnetometry capabilities designed and implemented by undergraduate and graduate students supported under this award. These home-built capabilities include vibrating sample magnetometry, laser vibrometry and Kerr magnetic microscopy, and serve the measurement needs of multiple researchers and small businesses across Oregon. Overall, the award has supported research experience for 5 graduate and 8 undergraduate students, resulting in over 20 presentations worldwide, 2 M.S. and 2 undergraduate theses; several journal and conference publications; and 1 patent application. In addition, these funds have supported K-12 outreach activities providing hands-on experience for grade and high-school students, and career counseling for freshmen students.
