Positron annihilation studies on chalcone chromophore doped PVA

Bhajantri, R. F. and Ravindrachary, V. and Harisha, A. and Ismayil, and Ranganathaiah, C. (2009) Positron annihilation studies on chalcone chromophore doped PVA. physica status solidi (c), 6 (11). pp. 2429-2431.

[img] Text (Full Text)
2429_ftp.pdf - Published Version
Restricted to Registered users only

Download (113Kb) | Request a copy
Official URL: http://dx.doi.org/10.1002/pssc.200982109


A novel organic non-linear optical material 1-(4-methylphenyl)-3-(4- N, N dimethyl amino phenyl)-2-propen-1-one (MPDMAPP) chalcone chromophore has been synthesized by standard method. Pure and MPDMAPP doped Poly(vinyl alcohol) films are prepared using solution casting method and characterized using UV-Visible absorption and Positron Annihilation Lifetime Spectroscopy. The optical spectroscopic study shows three absorption bands, 196-202 nm assigned to localized n →π * transitions, 205-320 nm to n →π * inter-band and 385-428 nm assigned to π →π * transition and arises due to the charge transfer complex. Using observed UV-Vis spectra, three optical energy gaps, Eg1 (4.96–4.25 eV), Eg2 (3.47–3.32 eV) and Eg3 (2.33–2.24 eV) have been estimated. The observed change in Eg upon doping is understood based on the formation of charge transfer complex arising from the –HC=CH– structure present in the composite and due to the interactions of dopant and OH group of PVA. The PALS results shows that the o-Ps lifetime decreases continuously as doping concentration increases and I3 initially increases (from 18.82 to 20.95) from 0 wt to 0.05 wt and then decreases gradually up to 16.76 for higher dopant concentrations with decrease in optical band gaps. The variation of positron data with Eg is understood by correlating the probability of Ps formation with the complex. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Item Type: Article
Uncontrolled Keywords: 33.50.Dq, 52.70.Kz, 68.55.Ln, 78.66.Qn, 78.70.Bj, 82.30.Rs
Subjects: Physical Sciences > Physics
Divisions: PG Campuses > Manasagangotri, Mysore > Physics
Depositing User: Dhruvakumar
Date Deposited: 08 Oct 2013 08:02
Last Modified: 08 Oct 2013 08:02
URI: http://eprints.uni-mysore.ac.in/id/eprint/15664

Actions (login required)

View Item View Item