Francis Xavier P A

@macollege.ac.in

Associate Professor, Department of Physics
Mar Athanasius College Kothamangalam

Francis Xavier P A


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https://researchid.co/pafxavier

EDUCATION

M Sc Physics, Ph. D.

RESEARCH, TEACHING, or OTHER INTERESTS

Condensed Matter Physics, Multidisciplinary, Materials Science, Renewable Energy, Sustainability and the Environment
12

Scopus Publications

258

Scholar Citations

8

Scholar h-index

8

Scholar i10-index

Scopus Publications

  • The Size-dependent variation of the optical properties of Bi-doped nickel tungstate
    H Hitha, Soumya Kuriakose, P. A Francis Xavier, Thomas Varghese
    Results in Surfaces and Interfaces, 2025
    Nickel tungstate samples doped with bismuth are synthesized by the method of direct chemical precipitation. The variation in the calcination duration leads to the size variation of Bi-doped NiWO 4 samples. It is widely recognised that calcination duration affects the structural parameters and changes their characteristics and functionalities. In the present work, it is found that the calcination duration affects the structural properties. X-ray diffraction (XRD) analysis is carried out to find the average crystallite sizes of the doped samples. The average crystallite size of the samples is found to increase with the increase in calcination duration, which is also confirmed with the W–H Analysis. The change in the structural parameters leads to a variation in the optical properties. UV–visible spectra of the samples show a shift in the absorption intensity and a slight change in the absorption peak. The variation in the spectra is due to the variation in the nanoparticle size. The energy gap also gets modified with the variation in the average crystallite size. An increase in the calcination duration leads to an increase in average crystallite size, and hence, the optical band gap reduces. This is by quantum confinement. The photoluminescence property is also modified by the change in the crystallite size. The emission colour of the sample varies significantly with the change in particle size. The emission spectrum of the sample with a longer calcination duration is found to have noteworthy differences from that of the sample with a shorter calcination duration. In that condition, transitions in the Bi 3+ ions start dominating, and the emission spectrum has a peak corresponding to the Bi transition. • Modification of the structural properties of Bi-doped nickel tungstate by varying calcination duration. • The variation of optical properties due to the structural variation. • Tuning of luminescence properties.
  • Highly conducting PANI- fMWNT composites with exceptional crystallinity and enhanced thermal stability for potential applications
    P.A. Francis Xavier, M.D. Benoy, Nidhi P. Ramesh, Thomas Varghese
    Journal of Solid State Chemistry, 2022
  • Enhanced electrical properties of polyaniline carbon nanotube composites: Analysis of temperature dependence of electrical conductivity using variable range hopping and fluctuation induced tunneling models
    P.A. Francis Xavier, M.D. Benoy, Seenamol K. Stephen, Thomas Varghese
    Journal of Solid State Chemistry, 2021
  • Orthophosphoric acid doped polyaniline carbon nanotube composites for anode layers of polymer LEDs
    P. A. Francis Xavier, Alanda Prince, Thomas Varghese
    Aip Conference Proceedings, 2020
    Among the conducting polymers, polyaniline (PANI) gains prime importance due to its relatively easy and cheap synthesis route, high yield of polymerization and tunable electrical and optical properties. By making composites with other suitable materials, the DC electrical conductivity of polyaniline can be improved. Multiwalled Carbon Nano Tube (MWNT) is one such material used for making composites of PANI to enhance the conductivity. Mechanical strength and thermal stability of the samples are also enhanced by making PANI-MWNT composites. Polyaniline-Multiwalled Carbon Nano Tube composites have been widely pursued in recent times owing to their enhanced electrical and thermal properties. In the present work, we have carried out systematic investigations on the temperature variation of DC electrical conductivity in orthophosphoric acid (H3PO4) doped PANI and H3PO4 doped PANI-MWNT composite samples in the form of pressed pellets. PANI-MWNT composites with various feed ratios have been synthesized by chemical oxidative polymerization technique using orthophosphoric acid as dopant. We have attempted a comparative study of the DC electrical conductivities of H3PO4 doped PANI and H3PO4 doped PANI-MWNT composites in bulk forms. The conductivity of these composites increases with increase in MWNT feed ratio and saturates at higher feed ratios. The highlight of the present investigations is the observation of high DC electrical conductivity in these samples, which stays almost constant from room temperature to 373K. The conductivity of the composites drops marginally with temperature, only above 373K. The conductivity in the 3-dimensional PANI-MWNT networks have been enhanced as compared to pure PANI sample. The observed enhancement in the DC conductivity can be explained in terms of the ‘bridging effect’ and ‘barrier resistance’. X-Ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR) Spectroscopic techniques were used to study the morphology of the samples.
  • Structural, mechanical and electrical characterization of polyaniline/polymethylmethacrylate blends
    P. A. Francis Xavier, Vyshakh Sreekumar, M. Amrithesh, Thomas Varghese
    Aip Conference Proceedings, 2020
    Polyaniline (PANI) has been widely studied as PANI has excellent electrical properties and good air stability. PANI also possesses attractive optical properties. Regardless of these interesting properties, polyaniline has only limited mechanical strength. Making composites/blends with other materials is one method for enhancing its mechanical strength and thermal stability. In the present work, attempts were made to enhance the mechanical strength and thermal stability of PANI by making PANI-Polymethylmethacrylate (PANI-PMMA) blends. PANI and PANI-PMMA blends have been synthesized using chemical oxidative polymerization technique using hydrochloric acid (HCl) as dopant. Emeraldine Salt (ES) forms of both PANI and PANI-PMMA samples were used in the present study. Fourier transform Infrared (FTIR) spectroscopy and Raman analysis were used to study the morphology of the samples. The peaks observed in the FTIR spectra are in good agreement with the reported values. The peaks in the FTIR and Raman spectra confirm the formation of PANI and PANI-PMMA blend. Thermo Gravimetric Analysis (TGA) of the samples reveals the thermal stability of the blends over PANI sample. The mechanical strength measurements depict that the strength of PANI-PMMA samples are higher than that of pure PANI. The compression strength of the PANI-PMMA samples increases considerably with increase in PMMA ratio. The compression strength is increased from 0.0811 N/m2for PANI to0.1409 N/m2for PANI-PMMA with the addition of 20% of PMMA by weight.
  • Effect of high energy electron beam irradiation on the structural and electrical properties of PANI-CaWO4 nanocomposite
    B. Rajesh Kumar, P. A. Francis Xavier, N. Aloysius Sabu, Thomas Varghese
    Aip Conference Proceedings, 2020
    In this work, a nanocomposite of PANI-CaWO4 is prepared by in situ oxidative polymerization of aniline monomer in an acidic medium in the presence of ammonium persulfate and CaWO4 nanoparticles. The prepared samples are subjected to different doses of high energy electron beam irradiation. The structural properties of the bare and irradiated samples are investigated using the X-ray diffraction technique, Fourier transform infrared spectroscopy and transmission electron microscopy methods. The DC and AC conductivity studies are carried out using the four probe and impedance analyzer methods respectively. The results of the systematic investigation show that the electron beam irradiation technique is an effective tool for tuning the structural and electrical properties of the PANI-CaWO4 nanocomposite for potential applications.
  • Aldehyde functionalized multiwalled carbon nanotubes to synthesize highly conducting polyaniline-MWNT thin films
    P.A. Francis Xavier, Gayathry Ajithkumar, Thomas Varghese
    Materials Today Proceedings, 2019
  • Effect of nickel doping on structural and magneto-optical properties of Fe3O4 ferrofluids
    P.A. Francis Xavier, Swapna S. Nair, M.R. Anantharaman
    Materials Today Proceedings, 2019
  • Enhanced photoluminescence in transparent thin films of polyaniline-zinc oxide nanocomposite prepared from oleic acid modified zinc oxide nanoparticles
    M. Sajimol Augustine, P.P. Jeeju, S.J. Varma, P.A. Francis Xavier, S. Jayalekshmi
    Thin Solid Films, 2014
  • Novel polypyrrole films with excellent crystallinity and good thermal stability
    Pullarkat P. Jeeju, Sreekanth J. Varma, Puthampadath A. Francis Xavier, Augustine M. Sajimol, Sankaran Jayalekshmi
    Materials Chemistry and Physics, 2012
  • Enhanced photoluminescence in oleic acid modified polyaniline
    M. Sajimol Augustine, S. J. Varma, P. A. Francis Xavier, S. Jayalekshmi
    Transactions of the Indian Institute of Metals, 2011
  • Thermal diffusivity measurements in PANI and PANI-MWNT composites using photo acoustic technique
    M. Amrithesh, P. A. Francis Xavier, V. Ganesh Chandraprabhu, S. Jayalekshmi, S. Thomas Lee, Jyotsna Ravi
    Transactions of the Indian Institute of Metals, 2011

RECENT SCHOLAR PUBLICATIONS

  • Effect of Dy3+ substitution on the structural and optical properties of BaWO4 nanoparticles-Visible emissions for optoelectronic applications
    SK Stephen, A Kumaran, H Hitha, PAF Xavier
    Materials Today: Proceedings , 2026
    2026
  • Synthesis and electrical properties of PANI/CeO2 nanocomposites: A study on the fluctuation-induced tunneling conduction
    PAF Xavier, A Suresh, DM Roy, B Binaya, P Prasad, NP Ramesh
    Materials Today: Proceedings , 2026
    2026
    Citations: 2
  • The Size-dependent variation of the optical properties of Bi-doped nickel tungstate
    H Hitha, S Kuriakose, PAF Xavier, T Varghese
    Results in Surfaces and Interfaces 20, 100592 , 2025
    2025
  • Harnessing the potential of iron oxide nanoparticles: A comprehensive review on their synthesis, functionalization and pharmaceutical innovations
    H Jijo, A Shamlath, A Abraham, F Xavier, S Chahal, A Numan, SM Simon
    Next Nanotechnology 8, 100270 , 2025
    2025
    Citations: 7
  • Effect of cobalt doping on the dielectric properties and electrical conductivity of nickel tungstate
    H Hitha, S Kuriakose, F Xavier, SK Stephen, M John, T Varghese
    Materials Today: Proceedings , 2023
    2023
    Citations: 1
  • Structural and Dielectric Characterization of Nanocrystalline BaWO 4
    SK Stephen, FPA Xavier, T Varghese
    Advanced Materials Research 1176, 119-127 , 2023
    2023
  • Structural and Dielectric Characterization of Nanocrystalline BaWO4
    S.K. Stephen, P.A.F. Xavier, T. Varghese
    Functional and Special Materials, 119-127 , 2023
    2023
  • Highly conducting PANI-fMWNT composites with exceptional crystallinity and enhanced thermal stability for potential applications
    PAF Xavier, MD Benoy, NP Ramesh, T Varghese
    Journal of Solid State Chemistry 316, 123638 , 2022
    2022
    Citations: 5
  • Enhanced electrical properties of polyaniline carbon nanotube composites: analysis of temperature dependence of electrical conductivity using variable range hopping and …
    PAF Xavier, MD Benoy, SK Stephen, T Varghese
    Journal of Solid State Chemistry 300, 122232 , 2021
    2021
    Citations: 24
  • Effect of high energy electron beam irradiation on the structural and electrical properties of PANI-CaWO 4 nanocomposite
    BR Kumar, PAF Xavier, NA Sabu, T Varghese
    AIP Conference Proceedings 2263 (1), 050015 , 2020
    2020
    Citations: 4
  • Orthophosphoric acid doped polyaniline carbon nanotube composites for anode layers of polymer LEDs
    PAF Xavier, A Prince, T Varghese
    AIP Conference Proceedings 2263 (1), 050007 , 2020
    2020
    Citations: 2
  • Structural, mechanical and electrical characterization of polyaniline/polymethylmethacrylate blends
    PAF Xavier, V Sreekumar, M Amrithesh, T Varghese
    AIP Conference Proceedings 2263 (1), 050004 , 2020
    2020
    Citations: 2
  • Effect of nickel doping on structural and magneto-optical properties of Fe3O4 ferrofluids
    PAF Xavier, SS Nair, MR Anantharaman
    Materials Today: Proceedings 25, 218-223 , 2020
    2020
    Citations: 5
  • Aldehyde functionalized multiwalled carbon nanotubes to synthesize highly conducting polyaniline-MWNT thin films
    PAF Xavier, G Ajithkumar, T Varghese
    Materials Today: Proceedings 25, 129-133 , 2020
    2020
    Citations: 7
  • Effect of 8 MeV electron beam irradiation on the structural, optical and electrical properties of a PANI-MnWO 4 nanocomposite
    N Aloysius Sabu, X Francis, S Ganesh, T Varghese
    The European Physical Journal Plus 134 (1), 42 , 2019
    2019
    Citations: 13
  • Investigations on Polyaniline Carbon Nanotube Composites with a Flat Temperature Response of Conductivity
    Francis Xavier P. A., Thomas Varghese
    Albertian Journal of Multidisciplinary Research 1 (1), 12-16 , 2019
    2019
  • Investigations on Some Magneto-Optical Properties of Nickel Doped Ferrofluids
    Francis Xavier P. A.
    Science and Society 16 (2), 103-112 , 2018
    2018
  • Highly Conducting PANI-MWNT Composites with a Flat Temperature Response of Conductivity
    Francis Xavier P. A., Thomas Varghese
    Science and Society 16 (1), 5-10 , 2018
    2018
  • Enhanced structural and optical properties of the polyaniline-calcium tungstate (PANI-CaWO 4 nanocomposite for electronics applications
    NA Sabu, X Francis, J Anjaly, S Sankararaman, T Varghese
    The European Physical Journal Plus 132 (6), 290 , 2017
    2017
    Citations: 18
  • Magnetic Field Dependence of Linear Dichroism for NixFe1-xFe2O4 Ferrofluids
    Francis Xavier P. A., Swapna. S. Nair, M. R. Anantharaman
    Science and Society 15 (1), 5-16 , 2017
    2017

MOST CITED SCHOLAR PUBLICATIONS

  • Novel polypyrrole films with excellent crystallinity and good thermal stability
    PP Jeeju, SJ Varma, PAF Xavier, AM Sajimol, S Jayalekshmi
    Materials Chemistry and Physics 134 (2-3), 803-808 , 2012
    2012
    Citations: 72
  • Synthesis and studies of exceptionally crystalline polyaniline thin films
    SJ Varma, F Xavier, S Varghese, S Jayalekshmi
    Polymer International , 2012
    2012
    Citations: 52
  • Enhanced electrical properties of polyaniline carbon nanotube composites: analysis of temperature dependence of electrical conductivity using variable range hopping and …
    PAF Xavier, MD Benoy, SK Stephen, T Varghese
    Journal of Solid State Chemistry 300, 122232 , 2021
    2021
    Citations: 24
  • Enhanced structural and optical properties of the polyaniline-calcium tungstate (PANI-CaWO 4 nanocomposite for electronics applications
    NA Sabu, X Francis, J Anjaly, S Sankararaman, T Varghese
    The European Physical Journal Plus 132 (6), 290 , 2017
    2017
    Citations: 18
  • Effect of 8 MeV electron beam irradiation on the structural, optical and electrical properties of a PANI-MnWO 4 nanocomposite
    N Aloysius Sabu, X Francis, S Ganesh, T Varghese
    The European Physical Journal Plus 134 (1), 42 , 2019
    2019
    Citations: 13
  • Enhanced photoluminescence in transparent thin films of polyaniline–zinc oxide nanocomposite prepared from oleic acid modified zinc oxide nanoparticles
    MS Augustine, PP Jeeju, SJ Varma, PAF Xavier, S Jayalekshmi
    Thin solid films 562, 84-89 , 2014
    2014
    Citations: 13
  • Enhanced shape anisotropy and magneto-optical birefringence by high energy ball milling in NixFe1-xFe2O4 ferrofluids
    SS Nair, F Xavier, PA Joy, SD Kulkarni, MR Anantharaman
    J. Magn. Magn. Mater 320, 815 , 2008
    2008
    Citations: 12
  • Enhanced photoluminescence in oleic acid modified polyaniline
    M Sajimol Augustine, SJ Varma, PA Francis Xavier, S Jayalekshmi
    Transactions of the Indian Institute of Metals 64 (1), 209 , 2011
    2011
    Citations: 11
  • Thermal diffusivity measurements in PANI and PANI-MWNT composites using photo acoustic technique
    M Amrithesh, PA Francis Xavier, VG Chandraprabhu, S Jayalekshmi, ...
    Transactions of the Indian Institute of Metals 64 (1), 133 , 2011
    2011
    Citations: 8
  • Harnessing the potential of iron oxide nanoparticles: A comprehensive review on their synthesis, functionalization and pharmaceutical innovations
    H Jijo, A Shamlath, A Abraham, F Xavier, S Chahal, A Numan, SM Simon
    Next Nanotechnology 8, 100270 , 2025
    2025
    Citations: 7
  • Aldehyde functionalized multiwalled carbon nanotubes to synthesize highly conducting polyaniline-MWNT thin films
    PAF Xavier, G Ajithkumar, T Varghese
    Materials Today: Proceedings 25, 129-133 , 2020
    2020
    Citations: 7
  • Highly conducting PANI-fMWNT composites with exceptional crystallinity and enhanced thermal stability for potential applications
    PAF Xavier, MD Benoy, NP Ramesh, T Varghese
    Journal of Solid State Chemistry 316, 123638 , 2022
    2022
    Citations: 5
  • Effect of nickel doping on structural and magneto-optical properties of Fe3O4 ferrofluids
    PAF Xavier, SS Nair, MR Anantharaman
    Materials Today: Proceedings 25, 218-223 , 2020
    2020
    Citations: 5
  • Effect of high energy electron beam irradiation on the structural and electrical properties of PANI-CaWO 4 nanocomposite
    BR Kumar, PAF Xavier, NA Sabu, T Varghese
    AIP Conference Proceedings 2263 (1), 050015 , 2020
    2020
    Citations: 4
  • Synthesis and electrical properties of PANI/CeO2 nanocomposites: A study on the fluctuation-induced tunneling conduction
    PAF Xavier, A Suresh, DM Roy, B Binaya, P Prasad, NP Ramesh
    Materials Today: Proceedings , 2026
    2026
    Citations: 2
  • Orthophosphoric acid doped polyaniline carbon nanotube composites for anode layers of polymer LEDs
    PAF Xavier, A Prince, T Varghese
    AIP Conference Proceedings 2263 (1), 050007 , 2020
    2020
    Citations: 2
  • Structural, mechanical and electrical characterization of polyaniline/polymethylmethacrylate blends
    PAF Xavier, V Sreekumar, M Amrithesh, T Varghese
    AIP Conference Proceedings 2263 (1), 050004 , 2020
    2020
    Citations: 2
  • Effect of cobalt doping on the dielectric properties and electrical conductivity of nickel tungstate
    H Hitha, S Kuriakose, F Xavier, SK Stephen, M John, T Varghese
    Materials Today: Proceedings , 2023
    2023
    Citations: 1
  • Effect of Dy3+ substitution on the structural and optical properties of BaWO4 nanoparticles-Visible emissions for optoelectronic applications
    SK Stephen, A Kumaran, H Hitha, PAF Xavier
    Materials Today: Proceedings , 2026
    2026
  • The Size-dependent variation of the optical properties of Bi-doped nickel tungstate
    H Hitha, S Kuriakose, PAF Xavier, T Varghese
    Results in Surfaces and Interfaces 20, 100592 , 2025
    2025