Investigations of the Epitaxial Growth and Characterization of High Perfection Magnetic Thin Films.
Final rept. Oct 86-Oct 91,
IBM ALMADEN RESEARCH CENTER SAN JOSE CA
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Methods of preparing high-perfection single crystalline films of 3d elements including Fe, Co and magnetic rare earths on semiconducting GaAs substrates have been investigated. The use of seed layers of Fe or Co a few monolayers thick, deposited onto GaAs001, followed by a Ag001 film, provided a suitable template for Fe epitaxy. This method avoided interfacial chemical reactions between Fe and the semiconductor, at the expense of introducing coherency strain and tilted epitaxy of the Fe. In the case of rare earths, intermediate seed films of rare earth trifluorides, grown onto GaAs111- provided a template for growth of c-axis oriented rare earth films and sandwich structures. These methods have enabled the effects of coherency strain on magnetic properties of Fe and rare earths to be investigated. Using an automated X-ray photoelectron diffraction XPD system we have investigated the growth and interfacial mixing of several key epitaxial systems including CoPt, CoAg, NdF3LaF3 and PtGaAs. Interfacial mixing in the interfaces of CoPt superlattices was confirmed, resulting in an alloyed region containing the ordered L12 phase CoPt3. Spin-polarized photoelectron diffraction SPPD experiments on MnF2 suggest a new , high-temperature magnetic ordering transition at 380K which is 313K above the Neel temperature.
- Solid State Physics