RAMBABU BOBBA
Department of Physics, Southern University
Baton Rouge, LA 70813,
(225)771-4130(V), 2493(V), 2310(fax), Email: Rambabu@grant.phys.sub.edu


Current Status: Tenured Professor, US Citizen

AREA(S) OF SPECIALIZATION

In Situ and Ex Situ   Characterization of materials using advanced surface analytical (STM, TEM, SEM and XPS ), X-ray Spectroscopic (EXAFS, NEXAFS) and Spectro-electrochemical (UV-VIS-NIR, XRD, DSC, TGA, and Impedance Spectroscopy ) Techniques

EDUCATION: Ph.D., 1982 Indian Institute of technology, Madras, India
                            MS., 1974 School of Studies in Physics, Vikram University. Ujjain,
                            BS., 1972 Andhra University, Waltair, India


TEACHING EXPERIENCE:            * Aug 1992- 1997 Associate Professor, Department of Physics, Southern University A&M College, Baton Rouge, Louisiana.
              1994 Huel D. Perkins Teacher of the Year, SUBR. 1993 College of Sciences Teacher of the Year, SUBR
                Aug 1986-Aug 1992 Asst. Professor, Southern Univ., Baton Rouge, LA

EXPERIENCE IN SERVICE LEARNING, EDUCATIONAL PROGRAMS AND RESEARCH COLLABORATIONS WITH NATIONAL LABORATORIES AND INDUSTRY

* Howard Hughes Biomedical Precollege and Outreach, Instructor, 1994- present
* NASA 2000 -SECTS, Instructor and Advisory Council Member, 1998


RESEARCH EXPERIENCE:

    * June 1995 - Aug. 1995

Physicist, Lawrence Livermore National Laboratory, Livermore, CA 94550. Worked with Fiber Optic Sensor development group. Studied the Ionic Optrodes and their role in the development of fiber optic sensors.     * June 1995 - Aug. 1994 Physicist, Lawrence Livermore National Laboratory, Livermore, CA-94550. Worked with Sensors group. Developed proposals for collaborative projects between Southern University and LLNL. Studied the rareearth impurities in ceria for sensor applications.    * May 1993 - Aug. 1993:     * May 1992 - Aug. 1992: Member of Technical Staff, AT&T Bell Laboratories. Allentown, PA-18103. Worked with CMOS technology development group. Involved in the process integration of .5 micron technology. Studied "Interdiffusion and Intermetallic formation of Al-Si-Cu/TiN/TiSi2/SiO2 system," Advanced Metallizations for ULSI Applications in 1993. University of California, Berkeley.     * May 1991- Aug. 1991: Member of Technical Staff, AT&T Bell Laboratories. Allentown, PA-18103. Worked with CMOS technology development group. Involved in the process integration of .9 micron technology. Studied "Formation of multiple TiSi2 on implanted profiles, dopant effects in polysilicon and diffusion kinetics of TiSi2/Polysilicon thinfilm couples. Ref.: Journal of Electronic materials, Vol. 22. No. 7. 1993.     * May 1990 - Aug. 1990: Member of Technical Staff, AT&T Bell Laboratories, Allentown, PA-18103. Worked with CMOS technology development group. Studied "Thermal Stability of TiSi2 and its impact on CMOS technologies." Also involved in the characterization of Rapid Thermally Annealed titanium films contacting silicide and non-silicide junctions. AT&T TM 52814-911608-01. Semiconductor Sci. Tech. 8(1993) 2023-2029.     * May 1989 - Aug. 1989: Research Associate, Corrosion Research Center, Department of Chemical Engineering, University of Minnesota, MN. Studied "Preparation and Characterization of Solid Electrolytes for Solid state Batteries and Sensors." Ref.: Journal of Material Science, Vol. 26 (1991), 2451-2457 2).     * May 1987 - Aug. 1987: Post Doctoral Fellow, Department of Chemistry, University of New Orleans, New Orleans, LA. Studied electron density distribution of metal alloys.     * March 1985 - Aug. 1986: Post doctoral Fellow, Department of Chemistry, University of New Orleans, LA. "Crystal structure determination of some selected inorganic complexes," Ref.: Journal of Inorg. Chem. Vol. 29, 2300-2307.     * March 1977 - March 1980: Senior Research Fellow, Department of Physics, Indian Institute of Technology, Madras-36, studied "Optical and Electrical Properties of Transition Metal Ions in Single Crystalline Solids." Ref.: Physica status solidi(b) 118,381 (1983) 2) Nuclear Instruments and Methods in Physics Research 356, ACN. 462-468(1984), and 3) Phys. Stat. Sol. (b) 118, 381 (1983).     * March 1974 - March 1977: Junior Research Fellow, CSIR. Worked on the project, "Development of Optical Memory Devices" using color centers in solids. Ref.: Phys sta sol (b) 90,465 (1978)

Gained experience in the operation of analytical instruments such as Carry 14 spectrophotometer, Varian E4 ESR, XRD, TEM and SEM. Worked with crystal growth furnaces such as bridgemann and kyropolus techniques. Experience with Four point probe PROMETRIX apparatus for sheet resistance and conductivity measurements.

RESEARCH INFRASTRUCTURE DEVELOPMENT:

Developed two research laboratories for Energy Conversion and Storage Devices(1.Solid State Ionics 2. Surface Science and Spectroscopy ) and to enhance the graduate education and materials research at Southern University. Worked consistently with staff scientists at LLNL , Dow Chem Co, and Lucent technologies (AT&T). Co-PI: Howards Hughes Biomedical Institute at SUBR.


RESEARCH PROJECTS/GRANTS [ 1995-present ]
  1. Preparation and Characterization of Solid Electrolytes for Solid Oxide Fuel Cells (DE-FG22-95MT95016).$104,242
  2. Thin Film Semiconductors for PV Applications (DE-05-95ER45549) $61,950
  3. Materials Science Research Instrumentation and Graduate Education at SUBR (NSF-ARI B839-101-7797) $294,560
  4. Fourier Tranform Infrared Spectrometer (NREL-EARLE Program) $120,000
  5. XAS OF Battery Materials, (DOE-SEA-CAMD beamline) B839-101-070, $108,500
  6. Development of Ionically Conducting Materials for Gas Phase Sensors (DE-FD03-95SF20799/A000) $27,432
  7. Synchrotron Radiation Studies of Structure and Rechargeability Relationships in FeS2 Battery system (UC subcontract #10401, #0949) $97,560/ Completed
  8. Solid State Thin Film Sensors (UC subcontract/LLNL)$59,600
  9. Thin Film Electrode-Electrolyte materials for Photoelectrochemical Cells, NREL $144,000
  10. Surface Morphology, Structural Integrity and Interfacial Kinetics of PbSO4 crystals during Cycling and Hydration in Lead Acid Batteries, $245,000, US. Army TACOM Center
    SELECTED PUBLICATIONS IN REFEREED JOURNALS : RAMBABU BOBBA B. Rambabu


    1. Ionic Optrodes: Role in Fiber Optic Chemical Sensors, Kevin Langry andB. Rambabu, Journal of Chemical and Biotechnology, 74-8: 1-16 (1999) ISSN 0268-2582
    2. X-ray Absorption Near Edge Spectroscopy (XANES) and Ionic Conductivity studies of rareearth dopants in CeO2, J. Hormes, Bryan Balazas and B. Rambabu, oral presentation in the 12th International Conference on Solid State Ionics, Greece, June 6-12, 1999, Journal of Solid State Ionics -1999. Ed. C. G. Vayenas
    3. Effect of low temperature synthesis on the structural and electrochemical properties of lithium silicate dried gells, N. Satyanarayana, B. Rambabu, oral presentation in the 12th International Conference on Solid State Ionics , Greece, June 6-12, 1999, Journal of Solid State Ionics -1999. Ed: C.G.Vayenas.
    4. Transport Properties and Battery Performance Studies of AgI-Ag2O-Se2O-P2O5, M. Venkateswarlu, N. Satyanarayana and B. Rambabu, Journal of Power Sources, 1999.
    5. Structural and Electrochemical Studies of Ionomeric Membranes and Carbon Supported Catalysts for DMFCs, B. Rambabu, J. Hormes, H. Modrow, and S. Noding, 38th Power Sources Conference, 8-11 June 1998, pp 447-480
    6. Contaminations and Impurities in DC Magnetron Sputtered WSix films, B. Rambabu and M.J.Sundhal, Physica. Stat. Solidi(a). 147, 477 (1995)
    7. Effect of Rapid Thermally Nitrided Titanium Films contacting silicided and non-silicided junctions. S.Chittipeddi, M.J.Kelly, C.M.Dziuba, V.C.Kannan, W.T.Cochran and B.Rambabu*. Journal of Elect. Materials Vol 22, No 7, 1993
    8. Effect of Dopants in Salicided Titanium Disilicided CMOS Structures: S.Chittipeddi, W.T.Cochran, andB.Rambabu: Semic. Sci.& Technol. 8(1993) 2023-2029.
    9. Integrity of Shallow Junction CMOS Structures with Ti/TiN/Al-Si-Cu and Ti/TiN/Al-Cu Contact Metalizations. S.Chittipeddi et al, W.T.Cochran, and B.Rambabu, Advanced metalizations for ULSI applications in 1993, UC, Oct 5-7, 1993, Solid State Electronics Vol 38, No 12, pp 2035-2040, 1995
    10. a.c conductivity and dielectric studies of silver based fast ion conducting glass system, M. Venkateswarlu,B. Rambabu and N. Satyanarayana, accepted for publication in the Journal of solid State Ionics, 1999.
    11. Design, Fabrication and Characterization of Solid State Batteries Made Up of Silverselenophosphate Glassy Materials, N. Satyanarayana, and B. Rambabu,38th Power Sources Conference, 8-11 June 1998, pp 390-394
    12. X-ray Absorption Spectra Near Edge Structure ( XANES ) of CdTe and ZnTe:Cu thin films for Solar Cells, Hartwig Modrow, J.Hormes, and B.Rambabu, AIP Proceedings on Photovoltaic Technologies, NREL, Denver, Co. March 1997
    13. Methanol Crossover in DMFCs: T. Page, L Shamona, S, Noding, J. Hormes, and B. Rambabu, presented in 11th International Conference on Solid State Ionics, Nov 16-22, Hawaii, www@Hawii.ssi-11-edu. Solid State Ionics, August-1998.
    14. Cyclic Voltammetry and XANES studies of Transition Metal Alloy Fuel Cell Catalysts and Ion Conducting Membranes, T. Page, S. Noding, H. Modrow , J. Hormes and B. Rambabu, submitted for publication, Journal of New Materials for Electrochemical Systems, 1999 Thermal Stability of TiSi2 and its Impact in CMOS Technologies, B. Rambabu, and S. Chittipeddi et al, AT&T Technical Memorandum, Document No. 52814-911608-01TM, Project 23991-1101
    15. Contaminations and Impurities in DC magnetron sputtered WSix films on SiO2: An analytical study, B. Rambabu and M. J. Sundhal et al, AT&T Technical Memorandum No 53825-930813, Project No. 23991-5555
    16. Silver Arsenate Electrolyte Batteries: Conduction Characteristics and Electrochemical Performance: P.S.S.Prasad and B.Rambabu. J. of Power Sources. Vol.34, 339-352, 1991
    17. Fast Ion Conducting Glasses: Effect of preparation on conductivity and correlation with surface analysis using Scanning Electron Microscopy: P.S.S.Prasad and B.Rambabu. Journal of Material Science. Vol 26, 2451-247,1991.
    18. Compositional dependent electrical conductivity in Silver Arsenite Solid Electrolytes: P.S.S.Prasad and B.Rambabu, Journal of Mat. Sci. Letters, Vol.9, 1066-1070, 1990
    19. Experimental Thin Film Deposition and Surface Analysis Techniques, B. Rambabu and W.Eugene Collins, Materials for Solid State Batteries, World Scientific Publishing Co, Singapore, pp 83-90, 1996 Ed: B.V.R.Chowdari and S.Radhakrishna
    20. Binuclear Molecular Incorporating Small Molecules as Bridging Ligands: magnetic and structural properties, Charles J, O’ Conner et al and B. Rambabu, J. of Inorganic Chemistry, Vol 25, No 14, 2300-2310, 1986
    21. Radiation Effects on Co and Ni doped NH4Cl Crystals, B. Rambabu, C. ramasastry amd B.V.R.Chowdary, Phys. Stat Solidi(b) 118, 381, 1983
    22. Cobalt Centers in Ammonium Chloride: optical absorption studies, B.Rambabu, C.Ramasastry and B.V.R.Chowdary, Phys. Stat. Solidi(b) 118,381, 1983
    23. Radiation Damage studies of transition metal dopants in Alkali Halides, B.Rambabu and B.V.R.Chowdary, Nuclear Inst & Methods, 356, ACN 462-468, 1984
    24. Optical Absorption bands of Cu:CsBr crystals,B. Rambabu, C.Ramasastry

      25. and B.V.R.Chowdari, Phys. Stat. Solidi(b) 90, 465, 1978.
    25. Transport and Surface Analysis of Arsenate. Glasses. P.S.S.Prasad and B.Rambabu. Journal of Solid State Ionics, North Holland Publishing Co. 1989.
    26. Recent Advances in FTIR. B.Rambabu anW.E.Collins.AnalyticalTechniques for Material Characterization. World Scientific publishing Co., Singapore. pp.335-345, 1987.
    27. XAS as a method to investigate doped and undoped CdTe and ZnTe thin Films for Solar Cells, B Rambabu, Josef Hormes and Hartwig Modrow, International Conference on Future Photovoltaic Technologies. NREL, Colarado, April 1997.
    28. XAS study of Polymers, J. Hormes and B. Rambabu, International Conference on Synchrotron Radiation, University of Windsor, Ca, June 1997.
    29. Photonics: Its Scope, Need, Supply and Demand in Emerging Undergraduate Education in 21st Century, Perry L. Walker, Isiaka Akanbi and B. Rambabu, proceedings of the ASEE Gulf Southwest Meeting, March 24-25, Vol 2, pp 683-692, 1994.
***** Over seventy conferance abstracts, full research reports and laboratory work books.

EXPERIMENTAL FACILITIES AND CURRENT RESEARCH PROFILE

1. SOLID STATE IONICS: Synthesis and Characterization of Solid Electrolytes for Fuel Cells, Batteries, Capacitors and Sensors.

The Solid State Ionics Laboratory in the Department of Physics has full spectrum of instrumental capabilities to investigate structure property relations of materials for enegy conversion and storage devices:. 1) Arbin Battery Cycling and testing (8 channel) unit, 2) Electrochemical Analyzer (EG&G PAR Model 273 Galvanostat/Potentiostat, 3) Solartron AC impedance analyzer), 4) Fuel Cell test station (Globe Tech), 5) Differential Scanning Calorimeter (DSC-10) and Thermogravmetric Analyzer (TGA, 6) Glove box, 7) high temperature furnaces and hydrostatic press for catalyst and MEA preparation and Sol Gel synthesis work station etc. The thrust area of our research centers around synthesis and characterization of low cost, light weight, low dielectric and high specific area solid oxide materials.. The objective is " fine tune " the desired properties through chemical and physical reorganization of solid state structure. Advanced in situ and ex situ characterization techniques are being used to study the structure, composition and mode of formation of surface layers on electrodes and electrolytes used in fuel cells and rechargeable batteries. We the faculty members and research staff at Southern University are focusing on low temperature synthesis ( Sol Gel process ), electrochemical characterization, membrane electrode assemblies (MEAs) and device development, where as our collaborators at Center for Advanced Microstructures and Devices (CAMD) are concentrating on investigating the structural properties using X-ray Absorption Spectroscopy (XAS). We have recently prepared and characterized the following systems using various spectroelectrochemical techniques such as XRD, FT-IR, DSC, TGA, SEM, EDS, NMR, XANES and :AC-impedance

  1. AgO2-SiO2 Gels for primary batteries
  2. Lithium silicate ( Li2O-SiO2 ) dried gels for high density rechargeable batteries.
  3. Ion conducting polymers ( perfluorinated ionomer Nafion ) for PEM fuel cels.
  4. Cathodic transition metal alloy and Pt-Ru/C electrocatalysts for Direct Oxidation of Methanol Fuel Cells
  5. Rare earth ion dopants in CeO2 for Solid Oxide Fuel Cells.
In future, we are planning to investigate: 1. structure property relationships inherent to the family of carbon aerogels and silicon aerogels . The preliminary work on aerogel catalysts are under progress and we have developed active collaborations with scientists at Livermore National Laboratory. We have earlier investigated the following systems: 1. Silver arsenate, silinophosphate and vanadate super ionic conducting (SIC) glasses for solid state primary batteries and electrode-electrolyte interfacial reactions in Li/SPE/FeS2, LiMnO2, LiCoO2 for secondary batteries. Our research projects in the Solid State Ionics Laboratory are funded by 1) US- DOE- OER, 2) US. DOE- LLNL, 2) US.DOE- LBL, 3) US. DOE-NREL, 4) US-Army- TACOM center and LEQSF.

CONTACT PERSON: PROFESSOR RAMBABU BOBBA Ph.D., rambabu@grant.phys.subr.edu, 225-771-2493 (V), 225-771-2310 (fax)

2. SURFACE SCIENCE AND SPECTROSCOPY LABORATORY[James Hall 114]

This laboratory is equipped with high vacuum scanning tunneling microscope [ HVC -STM ) [ Model 525 DT McAllister Technical Associates ], UV-VIS-NIR Optical absorption and fluorescence spectrometers with accessories for high and low temperature measurements, and several other miscellaneous research instruments for material science research. In addition, our laboratory is the official site for collaborative research with staff members at the Center for Advanced Microstructures and Devices ( CAMD ). At the storage ring of the CAMD, an X-ray beam line for material research is available. This beam is equipped with a double crystal vacuum monochromator ( DCM ) of the Lemmonier type for which several sets of crystals are available allowing measurements between about 700 eV and 18.000 kV. Thus it is possible to investigate all elements from Z = 9 (F) up to Z = 92 (U) at least at one suitable X-ray edge. XAFS, XANES, and EXAFS experiments can be carried out using the standard transmission technique and also using the total electron yield mode. A semiconductor detector (with a rather low resolution) for fluorescence detection is available but has to be taken into operation.

Our UHV chamber STM is equipped with several ports for the future inclusion of other surface science probes ( LEED, AES, TDMS, ISS, EELS and HREELS ) to study adsorption, desorption, chemical reactivity, surface atomic structure, interfacial morphology, work function and tribology i.e. friction in complex electrochemical, electronic nanostructured materials. With our STM, atomic resolutions has been obtained for Silicon, Germanium, Aluminium, Graphite, gold, platinum, rhenium, molybdenium etc. Our laboratory is conducive to synthesis and characterization of nanostructured and nanofabrication of device materials that include real supported catalysts and model catalysts and other advanced materials. Sol -gel , gas phase , high energy ball milling and sintering techniques are available to prepare nanometer sized crystallites that have a high surface to volume ratio. At this project site, we have found that the sol gel processing can be combined with supramolecular templating agents in deriving well defined porous structures. For nanofabrication. electron beam lithography and photolithography techniques are available at CAMD.

We have recently studied the XANES spectra of: 1) rare earth dopants in CeO2) for solid oxide fuel cells (SOFCs), 2) S- K edge of perfluorinated ionomers (Nafion) and carbon suppoted transition metal catalysts for direct oxidation of methanol fuel cells (DMFCs), 3) Fe and S K edges of FeS2, 4) K edges of LiMnO2 and LiCoO2 ,5) K edges of Cu doped and undoped CdTe and ZnTe thin films, and Ag and Si K edges of Ag2O -SiO2 sol gels.

The laboratory is primarily developed with the support of NSF-Academic Research Infrastructure ( ARI ) Program, US- DOE and LEQSF ( MS program funds ). However, at present this laboratory lacks a full time technical person to operate the above mentioned state of the art research instrumentation.

CONTACT PERSON: Professor Rambabu Bobba Ph.D., rambabu@grant.phys.subr.edu. , 225-771-2493 (V), 4130 (V) or 225-771-2310 (fax).


  Faculty of Department of Physics