Chandrasiri Ihalawela, a graduate student in Physics & Astronomy, presented twice on Optical and Electronic Materials and Devices – Fundamentals and Applications at the May 17-21, 2015, joint meeting of Deutsche Glastechnische Gesellschaf of the German Society of Glass Technology (DGG) and the Glass & Optical Materials Division of the American Ceramic Society (ACerSGOMD.)
Chandrasiri Ihalawela
This conference is the second of a two-year experiment to combine the American and German annual conferences in an effort to strengthen ties between U.S. and European glass researchers.
Ohio University co-authors on “Size Dependent Phase Transition Behavior of Amorphous Phase-change Sb2Te3 Nanowires” included graduate student Mayur Sundararajan; Dr. Martin Kordesch, Professor of Physics & Astronomy; and Dr. Gang Chen, Associate Professor of Physics & Astronomy.
Size Dependent Phase Transition Behavior of Amorphous Phase-change Sb2Te3 Nanowires
Abstract: Size, speed and efficiency are the major challenges of next generation non-volatile memory (NVM) needed to satisfy the requirements of future device applications. Reduction of effective memory cell size in conjunction with multilevel cells could be promising to achieve high data densities, but the size reduction may result in changes in material properties. If phase transition properties of the materials are also tunable with respect to the size, then more attractive solutions could be realized. The key for NV phase-change memory (PCM) is rapid switching between two stable phases with optical or electrical excitation. In this study, we report the phase transition properties of prototypical Sb2Te3 nanowires synthesized in anodic alumina matrices with a range of sizes from 20 to 200 nm through an electrochemical deposition method, which is the best technique to generate high aspect ratio nanostructures. Energy dispersive X-ray spectroscopy, X-ray diffraction, electron microscopy and electrical resistivity measurements were used to characterize the composition, structure, morphology, and phase transition properties. Modifications in phase transition properties respect to the different sizes of Sb2Te3 nanowires will be discussed in a broader perspective to obtain fundamental understanding of the size and 1D confinement effect of PCMMs. (GOMD-S4-017-2015) Size Dependent Phase Transition Behavior of Amorphous Phase-change Sb2Te3 Nanowires C. A. Ihalawela 1 ; M. Sundararajan1 ; X. Lin2 ; M. Kordesch1 ; G. Chen1 ; 1. Ohio University, USA; 2. Argonne National Lab, USA
Growth Mechanism of Amorphous Sb2Te3 Thin Films and Nanowires Prepared by Electrochemical Deposition
Ihalawela also presented a poster on “Growth Mechanism of Amorphous Sb2Te3 Thin Films and Nanowires Prepared by Electrochemical Deposition.” His co-authors were Sundararaja, Chen and Kordesch.
Abstract: Exhibiting a rapid phase transition triggered by an optical or electric pulse excitation and followed by significant changes in optical and electric properties is a key feature of phase change memory materials (PCMMs) and backbone of the non-volatile PCM devices. One of the challenges is however to downsize the materials to match the shrinking size of the devices. In this study, an electrochemical method has been employed, mainly because of its excellent void -filling capability, for the synthesis of amorphous Sb2Te3 PC thin films and nanowires. The contribution of main influential parameters, such as electrolyte depletion, mass transportation, E-field modification, restricted diffusion, and reduction-surface stability to the growth of the amorphous materials has been studied using chronoamperometry curves. Energy dispersive X-ray spectroscopy, X-ray diffraction and electron microscopy have been used to characterize the composition, structure and morphology of the materials. It has been found that the growth mechanism of amorphous nanowires is different from that of thin films and significantly different from that of metallic nanowires. It is hoped that our study will shed light on the growth mechanism of amorphous nanowires prepared by electrodeposition and benefit their device applications.(GOMD-SP-P022-2015) Growth Mechanism of Amorphous Sb2Te3 Thin Films and Nanowires Prepared by Electrochemical Deposition C. A. Ihalawela 1 ; M. Sundararajan1 ; X. Lin2 ; M. Kordesch1 ; G. Chen1 ; 1. Ohio University, USA; 2. Argonne National Lab, USA
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