Growth and Patterning of Epitaxial Multiferroic Nanocomposites Using Pulsed Electron Deposition
CoFe2O4 (CFO) offers unique properties as a magnetoelectric material due to its large magnetoelastic response when strained. Previous work has shown that when CFO is co-deposited with BiFeO3 (BFO) nanostructured phase segregation occurs, with CFO pillars forming in a BFO matrix, and that electrical control of the magnetic anisotropy is possible.
The CFO-BFO nanocomposite system has been proposed as a possible electrically-controlled spintronic logic or memory scheme. In this talk, I will discuss work I have performed at UVA as part of my dissertation to grow and pattern high quality CFO-BFO nanocomposites using the novel pulsed electron-beam deposition (PED) technique.
The relatively new PED technique is similar to the more traditional pulsed laser deposition (PLD) approach, but steps must be taken to ensure good film quality. I will briefly discuss how we have optimized the PED growth process to achieve layer-by-layer epitaxial growth of complex oxides. I will then discuss our work growing CFO-BFO nanocomposites using PED and explain the difference in magnetic properties that we see due to the different growth technique.
Then I will discuss the new technique we have developed to direct the self-assembly of the CFO pillars in CFO-BFO nanocomposites using electron-beam lithography.  Our recent results have demonstrated the ability to pattern the nanocomposites into square arrays of pillars with pillar spacing as small as 100 nm.
 F.Zavaliche, et al. Nano Lett. 7 (2007).
 S.A. Wolf, et al. Proc. IEEE 98 (2010).
 R. Comes, et al. J. App. Phys. 111 (2012).
 R. Comes, et al. Nano Lett. 12 (2012).