The grant explores development of pulsed laser deposition (PLD) assisted self-organized growth of uniform magnetic nanoparticles (islands) of ideal shape, dimension, and concentration in different thin film matrices. The magnetic nanoparticle materials will be constituted of both single elements (such as Fe, Co, Ni, etc.) and multielemental alloys (such as Fe-Pt, Sm-Fe-Ti, etc.). The matrix materials will be constituted of nonmagnetic oxide (such as Al2O3 and SiO2) and nitride (such as TiN, AlN). The substrate temperature, laser energy density determining the number density of arriving adatoms on substrate surface, and pressure of the gas ambient will be varied to control the size, shape and volume fraction of magnetic nanoparticles. The self-assembled nanocomposites developed in this project will provide a range of materials for magnetic properties measurements and analyses. The goal is to use advanced microstructural techniques such as scanning transmission electron microscopy with atomic number contrast (STEM-Z) and electron energy loss spectroscopy (EELS) with atomic size probe to determine the structures of the interfaces as well as the local chemistries and the effects of segregation and interaction between the nanoscale building blocks and their surroundings.
The broader impacts of the proposed activity will be the development of (i) a new method for selfassembly of nanomagnetic particles with narrow particle size distribution, (ii) a fundamental understanding on magnetic properties at the nanoscale, (iii) new techniques for three-dimensional reconstruction of nanoparticle shape from atomic resolution Z-contrast images, and (iv) research and education programs for graduate and undergraduate students in the area of nanotechnology.
