User:Dr Rama Devi Vummadi/sandbox

Objective:

To pursue a postdoctoral research in your esteemed research group that would further enrich my experience and creativity in Material Chemistry & Nanomaterials.

Summary:

•Over 9+ year’s experience in Scientific Research Organizations.

•Good exposure in Material & Nanomaterials Synthesis.

•Familiar with analytical instruments (as powder XRD, FT-IR, Raman spectroscopy, XPES, ESR, TEM, SEM, EDS, DRS, ICP-AES, absorption and emission (photoluminescence).

•Capable to interpretation of analytical results obtained from various analytical instruments.

Education:

• Ph.D. (Materials Science & Nanomaterials) Thesis Title: Preparation, Characterization and Spectral studies of Pyrochlores and Tungstates

• Research Supervisor: Prof. M. Vithal (Material Chemistry), Department of Chemistry, Osmania University, Hyderabad, India.

• '''M. Sc. (Master of Science)''' in Physical Chemistry, Department of Chemistry, Osmania University, Hyderabad, India.

• '''B. Sc. (M.P.C)''' (Bachelor of Science), Osmania University, Hyderabad, India.

Research Experience:

 Gained experience in the synthesis of pyrochlore type compounds, tungstates and NASICON type compounds by citrate sol-gel method.

 Gained experience in the basic characterization techniques such as powder XRD, FT-IR, Raman spectroscopy, XPES, ESR, TEM, SEM, EDS, DRS, ICP-AES, absorption and emission (photoluminescence).

 DC conductivity (by two probe method) measurements as a function of temperature and photocatalytic activity for YLnTi2O7 (Ln = Nd, Sm, Eu and Gd) were carried out.

 The Photocatalytic activity and AC Conductivity studies of pyrochlore type YLnTiZrO7 (Ln = La, Nd, Sm and Eu) were carried out

 Effect of crystallite size on electron resonance of Gd3+ and luminescence of Eu3+ Doped in La6WO12 (Rare earth tungstate) has been studied

 Used Rietveld refinement for structural refinement of crystalline materials.

 Synthesis of oxide materials such as Ta2O5, Nb2O5 using pressure cooker experiment. Synthesis of mesoporous materials namely SBA-15 by hydrothermal method.

Preparation of pyrophosphates and borates by solid state metathesis reactions

Instruments Handling:

 Powder XRD (Shimadzu-S7000), FT-IR (Perkin Elmer), Raman spectra (BRUKER), UV-Vis Spectrophotometer, Spectrofluorometer (JASCO FP-777).Photo reactor,

Fellowships and Awards:

 Senior Research Fellow award from CSIR (Council of Scientific and Industrial Research), New Delhi, Govt. of India, 2010-2013.

 Research Fellowship in Department of Chemistry, Osmania University 2006-2010.

Computer and Software Skills:

Sci-Finder, Patents Search, MS Word, Power Point, Chem. Draw, ISIS draw, preparation of research reports, manuscripts and project proposal preparation.

Accomplishments in Doctoral Research:

Ph.D. Research Fellow in the field of Material Chemistry & Nanomaterials at Department of Chemistry, Osmania University, Hyderabad, India. During the course of my doctoral research work I have carried out my research work thesis entitled “Preparation, Characterization and spectral studies of Pyrochlores and Tungstates”. Pyrochlore oxides are used as materials for immobilization of actinide-rich wastes, as electrolytes in solid state fuel cells, as combustion catalysts, as chemical sensors and as photocatalysts. These materials exhibit variable ionic and electronic conductivity which is related to cation (A and B) and oxygen anion vacancies and high temperature stability. I have prepared new pyrochlore type compositions YLnTiZrO7 (Ln = La, Nd, Sm, and Eu) by sol-gel method. All the prepared compounds were characterized by powder X-ray diffraction (XRD), Rietveld refinement, Raman spectroscopy, X-ray photoelectron Spectroscopy (XPES) and Diffused reflectance spectroscopy (DRS). The photocatalytic activity and impedence spectral features were studied. These results are published in Ionics (2014) 20, 373-380.

The bulk and nano particles of pyrochlore YLnTi2O7 (Ln = Nd, Sm, Eu and Gd) have been prepared by sol-gel method using titanium peroxo complex as one of the starting material. These compounds were characterized by TGA-DTA, Powder XRD, Raman, EDS, XPES, and UV-Visible diffuse reflectance spectra. The photocatalytic activities of all the nano powders were evaluated by photodegradation of methylene blue under visible light irradiation.The DC conuctivity of all these materials was carried out in the temperature range 180 - 600 oC and discussed. These results are published in Transactions of Indian Ceramic Society vol. 72, no. 4, pp. 241-251 (2013).

Nano sized Eu3+ and Gd3+ doped lanthanum tungstates of composition La6-xLnxWO12 (Ln = Eu, Gd; 0 ≤ x ≤ 0.2) were prepared by sol-gel complexation method. These materials were characterized by Powder X-ray diffraction (XRD). The average crystallite size was calculated from the line width of intense line of powder XRD using Scherer’s equation. The Electron Spin Resonance (ESR) spectra of Gd3+ doped lanthanum tungstate La6-xGdxWO12 gave characteristic “U” type spectrum. The luminescence spectra of Eu3+ doped La6-xEuxWO12 gave typical emission bands expected for trivalent europium ions. The effect of particle size on the ESR and luminescence spectra was studied. These results are published in Indian Journal of Engineering and Materials Science 19 (2012) 204-208.

Bulk and nano sized NbTi(PO4)3 (NASICON) has been prepared by sol-gel method using peroxo titanium complex as one of the reactant and ethylene glycol as gelating reagent. The compound was characterized by powder XRD and IR. The morphological characterization was carried out by transmission electron microscopy. The crystallite size was estimated from the line width of intense powder diffraction line using Scherrer’s formula and TEM images. These results are published in Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano Metal Chemistry 40 (2010) 883-887.

I am also involved in the work of my research group members in the preparation of pyrophosphates, borates and perovskite type of materials by solid state metathesis, coprecipitation and solid state (conventional) methods. These results are published in

Journal of Applied Physics 108 (2010) 044906,

Journal of Solid State Chemistry 184 (2011) 264-272,

Materials Research Bulletin 46 (2011) 1219-1226,

Spectroscopy Letters 44 (2011) 258-266,

Ceramics International 36 (2010) 1485-1489,

'''Int. J. of Nanotechnology (2010) 1077-1086,'''

Spectrochimica Acta A 74 (2009) 726-730,

Bulletin of Materials Science 32 (2009) 1-10,

Materials Chemistry and Physics 108 (2008) 319.

List of Publications:

(13) Preparation, Characterization, Photocatalytic activity and Conductivity studies of YLnTiZrO7 (Ln = La, Nd, Sm and Eu)

V. Rama Devi, G. Ravi, Radha Velchuri, C.H. Sameera Devi, G. Prasad, and M.Vithal

Ionics (2014) 20, 373–380.

(12) Preparation, Characterization, Photocatalytic activity and Conductivity studies of YLnTi2O7 (Ln = Nd, Sm, Eu and Gd)

V. Rama Devi, G. Ravi, Radha Velchuri, N. R. Munirathnam, G. Prasad, and M.Vithal

'''Trans. Ind. Ceram. Soc, vol. 72, no. 4, pp. 241-251 (2013).'''

(11) Effect of crystallite size on electron resonance of Gd3+ and luminescence of Eu3+ doped in La6WO12

V. Rama Devi, B. Vijaya Kumar, Radha Velchuri, Palla Suresh, G. Ravi and M. Vithal

Indian Journal of Engineering & Materials Science 19 (2012) 204-208.

(10) Low temperature Sol-Gel Synthesis of bulk and nanosized NbTi(PO4)3

V. Rama Devi, Radha Velchuri, B. Vijaya Kumar, K. Ravi Kumar and M.Vithal

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano Metal Chemistry 40 (2010) 883-887.

(9) Preparation, characterization, emission (Eu3+) and electron spin resonance (Gd3+)studies of Y2-xLnxTi2O7(Ln= Eu and Gd, x = 0.0, 0.05)

B. Vijaya Kumar, Radha Velchuri, V. Rama Devi, G. Prasad, B. Sreedhar, C. Bansal and M. Vithal

Journal of Applied Physics 108 (2010) 044906.

(8) Preparation, Characterization, Magnetic susceptibility (Gd, Sm and Eu) and XPS Studies of Ln2ZrTiO7 (Ln = La, Eu, Dy and Gd)

B. Vijaya Kumar, Radha Velchuri, V. Rama Devi, B. Sreedhar, G. Prasad, D. Jaya Prakash M. Kanagaraj, S. Arumugam and M. Vithal

Journal of Solid State Chemistry 184 (2011) 264-272.

(7) Preparation and Characterization of Rare Earth Orthoborates, LnBO3 (Ln = Tb,La, Pr, Nd, Sm, Eu, Gd, Dy, Y) & LaBO3: Gd, Tb, Eu by Metathesis Reaction: ESR of LaBO3: Gd and Luminescence of LaBO3: Tb, Eu.

Radha Velchuri, B. Vijaya Kumar, V. Rama Devi, G. Prasad, D. Jaya Prakash and M. Vithal

Materials Research Bulletin 46 (2011) 1219-1226.

(6) Solid state metathesis synthesis, characterization and spectral studies of rare earth doped Sr1-xLn2x/3MgP2O7 (Ln = Gd, Eu, Dy, Sm, Pr and Nd; x = 0.05)

Radha Velchuri, B. Vijaya Kumar, V. Rama Devi, D. Jaya Prakash and M. Vithal

Spectroscopy Letters 44 (2011) 258-266.

(5) Solid state metathesis synthesis of BaTiO3, PbTiO3, K0.5Bi0.5TiO3 and Na0.5Bi0.5TiO3

Radha Velchuri, B.Vijaya Kumar, V. Rama Devi, G. Prasad and M.Vithal

Ceramics International 36 (2010) 1485-1489.

(4) Low temperature preparation of NaTi2(PO4)3 by sol-gel method

Radha Velchuri, B. Vijaya Kumar, V. Rama Devi, Sang Il Seok and M. Vithal

'''Int. Journal of Nanotechnology (2010) 1077-1086.'''

(3) Low temperature, preparation and characterization of In1-xLnxBO3 (x = 0.0 and 0.05; Ln= Gd, Eu, Dy and Sm): ESR of In0.95Gd0.05BO3 and emission of In0.95Eu0.05BO3

Radha Velchuri, B.Vijaya Kumar, V. Rama Devi, K. Ravi Kumar, G. Prasad and M. Vithal.

Spectrochimica Acta A 74 (2009) 726-730.

(2) Preparation and characterization studies of metal borates, Cu1-xMxB2O4 (M = Ni, Co and Mn; x = 0, 0.1 and 0.5)”

N. Anantharamulu, B.Vijaya Kumar, V. Rama Devi, T. Sarojini, Ch. Anjaneyulu and M.Vithal

Bulletin of Materials Science 32 (2009) 1-10

(1) Preparation, characterization and spectral studies of Cr1−xEuxBO3 (x = 0, 0.01 and 0.05)

N. Anantharamulu, B. Vijaya Kumar, V. Rama Devi, M. Vithal

Materials Chemistry and Physics 108 (2008) 319