Nanocomposite thin films composed of oriented Co50Pt 44Cu6 nanoparticles embedded in a MgO matrix has been synthesized by rf-magnetron co-sputtering onto NaCl(001) substrates kept at 620 K. As the sputtering power increases, (001) orientation is improved and atomic ordering is also promoted. However, superlattice reflections are quite weak and the ordered region is limited in local area of the nanoparticles, indicating low degree of order. Electron diffraction and elemental mapping revealed that additive Cu is alloyed with CoPt. We have also fabricated (Co 26Fe20)Pt44Ag10SiO2 nanocomposite thin films at 675K for comparison. Atomic ordering is promoted by Fe and Ag addition as well as higher substrate temperature; however, it was found that ternary element (Cu, Ag, Fe) addition into CoPt alloy is not so effective to promote atomic ordering. Origin of the slow ordering kinetics is discussed using thermodynamical parameters.
ASJC Scopus subject areas
- 化学 (全般)