Structural Aspects of Nanometer Size Amorphous Materials

seminars
16.05.2019
14:30
אודיטוריום ע " ש דיוויד וואנג , קומה 3, בנין דליה מידן
Mrs. Yael Etinger-Geller, Ph.D. Candidate

Mrs. Yael Etinger-Geller, Ph.D. Candidate

Department of Materials Science and Engineering,
Technion – Israel Institute of Technology Haifa 3200003, Israel

Crystallization in the course of biomineralization, often occurs via an amorphous precursor phase, allowing additional control over the mineralization process. One of the main advantages of this method is that it enables organisms to exert control over the resulting polymorph, which is not necessarily the thermodynamically-stable one, by manipulating the short-range order of the amorphous phase. Although many aspects of science and technology rely on amorphous materials, considerably less research focuses on the structure of amorphous materials as compared to their crystalline counterparts. In this research, we draw inspiration from nature and study the ability to control the short-range ordering in amorphous materials via nanometer size effects. We chose atomic layer deposition (ALD) to deposit thin amorphous oxides; this technique that can provide extremely precise, sub-nanometric, thickness control and can deposit conformal and pinhole-free amorphous films of various materials. Amorphous thin films of different oxides, deposited by ALD, were characterized by EELS, XPS, SS-NMR and GI-XANES at the synchrotron and found to vary structurally as a function of size. These atomistic alterations were also found to affect the amorphous thin film’s average density, and other density-related properties. We believe that the ability to tune one property or another solely by size, can open new possibilities for materials selections and applications, in science and technology.

  1. Y. Etinger-Geller et al., Chem Mater, 2017, 29
  2. Y. Etinger-Geller et al., J Appl Phys, 2019, 12

Advisor: Prof. Boaz Pokroy