جهت دسترسی به کاربرگه ی زیر، از این لینک استفاده کنید. http://dl.pgu.ac.ir/handle/Hannan/66287
Title: Ultra-low frequency Raman spectroscopy of SWNTs under high pressure
Keywords: Science & Technology;Technology;Physical Sciences;Engineering, Electrical & Electronic;Materials Science, Multidisciplinary;Optics;Engineering;Materials Science;Single walled carbon nanotubes;Raman spectroscopy;squash mode;high pressure;WALLED CARBON NANOTUBES;VIBRATIONAL-MODES;SINGLE;BUNDLES;SENSORS
Issue Date: 15-Feb-2017
Publisher: Society of Photo-optical Instrumentation Engineers (SPIE)
Description: Radial deformation phenomena of carbon nanotubes (CNTs) are attracting increased attention because even minimal changes of the CNT's cross section can result in significant changes of their electronic and optical properties. It is therefore important to have the ability to sensitively probe and characterize this radial deformation. High pressure Raman spectroscopy offers a general and powerful method to study such effects in SWNTs. In this experimental work, we focus in particular on one theoretically predicted Raman vibrational mode, the so-called "Squash Mode" (SM), named after its vibrational mode pattern, which has an E2g symmetry representation and exists at shifts below the radial breathing mode (RBM) region. The Squash mode was predicted to be more sensitive to environmental changes than the RBM. Here we report on a detailed, experimental detection of SMs of aligned SWNT arrays with peaks as close as 18 cm-1 to the laser excitation energy. Furthermore, we investigate how the SM of aligned CNT arrays reacts when exposed to a high pressure environment of up to 9 GPa. The results confirm the theoretical predictions regarding the angular and polarization dependent variations of the SM's intensity with respect to their excitation. Furthermore, clear Raman upshifts of SM under pressures of up to 9 GPa are presented. The relative changes of these upshifts, and hence the sensitivity, are much higher than that of RBMs because of larger radial displacement of some of the participating carbon atoms during the SM vibration. These novel ultra-sensitive Raman SM shifts of SWNTs provide enhanced sensitivity and demonstrate new opportunities for nano-optical sensors applications.
URI: https://dx.doi.org/10.1117/12.2236463
Other Identifiers: http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000389673700003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
978-1-5106-0255-7
1996-756X
http://hdl.handle.net/10044/1/44197
Type Of Material: Other
Appears in Collections:Chemistry

Files in This Item:
There are no files associated with this item.


تمامی کاربرگه ها در کتابخانه ی دیجیتال حنان به صورت کامل محافظت می شوند.