Metals | Materials Science and Engineering at Penn State

Faculty that work in the area of Metals

Venkatraman Gopalan

Venkatraman Gopalan
Professor of Materials Science and Engineering
Associate Director, Center for Optical Technologies
N-212 Millennium Science Complex
(814) 865-2910
gopalan@matse.psu.edu
http://www.mri.psu.edu/Faculty/Gopalan/

Biographical Sketch:

Dr. Gopalan received his B.Tech. in Metallurgical Engineering from the Indian Institute of Technology, Chennai, in 1989, and his Ph.D. in Materials Science and Engineering from Cornell University in 1995. He was a postdoctoral scholar in the Electrical and Computer Engineering Department at the Carnegie Mellon University from 1995-1996, and was subsequently awarded a director funded postdoctoral fellowship at the Los Alamos National Laboratory, where he performed research on ferroelectrics and electro-optics till 1998.

He joined Pennsylvania State University as an assistant professor in December 1998, and became a full professor in 2007. He has been awarded the National Science Foundation CAEEER award (2000), Robert R. Coble Award from the American ceramics Society (2002), Corning Faculty fellowship in Ceramic Sciences (2004), National Research Council Faculty Fellowship (2004), Wilson award for excellence in research (2005), Eshbach Faculty Fellow at the Northwestern University (2007), Richard M. Fulrath award from the American ceramics Society (2009).

He is the associate director of the Center for Optical Technologies since 2003, has served on the editorial board of the Annual Reviews of Materials research since 2004, and served as the Chairman of the User Executive Committee for the Center for Nanophase Materials Science, Oak Ridge National Laboratory, in 2010-11. Gopalan has published over 150 papers, and has written five book chapters on ferroelectric complex oxides, nonlinear optics, optical metamaterials, and scanning probe microscopy.

Research Interests:

Optical materials
Electro-optics
Ultrafast nonlinear optics
Scanning probe microscopy
Near-field optical imaging
Ferroelectrics
Ferromagnets
Semiconductors
Photonic crystals structures
Electromagnetic wave modeling
Phenomenological modeling

Areas of Research:

Our research focuses on the science and technology of nonlinear optical materials. The work straddles materials science, physics, and optical engineering. We have three areas of current interest:

Multiferroics: Multiferroics are an exciting class of materials that have co-existing ferroelectricity and magnetism. To study the coupled dynamics of electrical and magnetic domains, we are performing real-time nonlinear optical probing with simultaneous measurement of coupled properties such as magnetoelectric effect, electro-optic and magneto-optic effects, hysteresis, and dielectric spectroscopy. The nanoscale structure of single domain walls is studied using scanning probe techniques such as piezoelectric force-, magnetic force-, nonlinear dielectric-, electric force- , and near-field scanning optical microscopies. Modeling tools include Ginzburg-Landau phenomenology, finite element method, and electromagnetic simulations.
Nonlinear optical devices: We are developing a new class of devices by integrating diverse optical functionalities, such as optical frequency conversion, beam steering, dynamic focusing, beam shaping and high-speed switching, on a single ferroelectric chip by microengineering ferroelectric domains into gratings, lenses, prisms, and other arbitrary shapes.
Hybrid semiconductor-metal-oxide nanostructures: In a recent breakthrough with Badding group (Chemistry), we have demonstrated microstructured silica optical fibers which contain hundreds of extreme aspect ratio (~105) semiconductor and metal-filled nanowires in a highly periodic array. We are currently characterizing light guiding and nonlinear optical responses of these hybrid fibers.

Experimental tools include ultrafast femtosecond lasers, electro-optics and fiber optics, scanning probe microscopies, dielectric and magnetic measurements, clean room, cryogenics, and simulations based on home-written MATLAB as well as commercial codes.

Technology Impacted By Research:

Multiferroics enable electrical control of magnetic devices, and vice versa, and dual electrical-magnetic storage media. Nonlinear optical devices are targeted for optical communications and infrared applications. The vision of hybrid semiconductor-metal-silica structures is all-fiber optoelectronics, where light generation, modulation and detection can be performed within a fiber.

Journal Articles and Publications:

V. Gopalan, D. B. Litvin, “New symmetries in crystals and handed structures,” Nature Materials , DOI: 10.1038/nmat2987 (2011). http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2987.html
J. R. Sparks, R. He, Noel Healy, M. Krishnamurthi, A. C. Peacock, P. J.A. Sazio, V. Gopalan, and J. V. Badding, “Low loss ZnSe Optical Fiber Waveguides,” Advanced Materials, 23, 1647-1651 (2011).
A. Vasudevarao, A. N. Morozovska, I. Grinberg, S. Bhattacharya, Y. Li, S. Jesse, P. Wu, K. Seal, S. Choudhury, E.A. Eliseev, S. Svechnikov, D. Lee, S. Phillpot, L.Q. Chen, A. M. Rappe, V. Gopalan and S.V. Kalinin, “Correlated polarization switching in the proximity of a 180 degree domain wall,” Phys. Rev. B. 82, 024111 (2010).
J. H. Lee, L. Fang, E. Vlahos, X. Ke, Y. W. Jung, L. Fitting Kourkoutis, J.W. Kim, P. Ryan, T. Heeg, M. Roeckerath, V. Goian, M. Bernhagen, R. Uecker, P. C. Hammel, K. M. Rabe, S. Kamba, J. Schubert, J. W. Freeland, D. A. Muller, C. J. Fennie, P. Schiffer, V. Gopalan, E. Johnston-Halperin & D. G. Schlom, “Creating a Strong Ferroelectric Ferromagnet via Spin-Phonon Coupling,” Nature 466, 954 (2010).
I. A. Temnykh, N. F. Baril, Z. Liu, J. V. Badding, V. Gopalan, “Optical multistability in a silicon-core silica-cladding fiber,” Optics Express, 18, 5305-5313 (2010).

Gopalan

Tarasankar DebRoy

Tarasankar DebRoy
Professor of Materials Science and Engineering
115 Steidle Building
(814) 865-1974
debroy@matse.psu.edu

Visit Dr. DebRoy's group website

Biographical Sketch:

Tarasankar DebRoy obtained his Ph.D. from Indian Institute of Science, Bangalore and did his postdoctoral work at Imperial College, London and MIT before joining Penn State where he is a Professor. Prof. DebRoy’s work includes four edited books and 280 papers on computational materials processing, particularly in the application of numerical transport phenomena and optimization in welding. His papers have been cited over 3900 times in the literature.
Work of his many graduate students (21 PhDs) have been recognized by prestigious awards from American Welding Society (AWS), ASM International, American Iron and Steel Society, The International Institute of Welding (IIW), The American Vacuum Society, The University of Graz and The Pennsylvania State University. Professor DebRoy is an Honorary Member and Fellow of AWS and a Fellow of ASM International. His awards include The Yoshiaki Arata Award of IIW, Kenneth Easterling Best Paper Award of the University of Graz and IIW, The 57th Comfort A. Adams Lecture Award of AWS, and the Faculty Scholar Medal of Penn State.
He has given 14 keynote/plenary lectures in international conferences and numerous invited lectures in many prestigious institutions in Australia, Austria, Canada, China, Egypt, India, Japan, Sweden, Taiwan, Ukraine and USA. He is a Founding Editor of “Science and Technology of Welding and Joining,” and serves as a Principal Reviewer of Welding Journaland as the Chair of the Research and Development Committee of AWS.

Research Interests:

Computational materials processing
Welding
Optimization
Numerical heat transfer, fluid flow and mass transfer
Monte Carlo simulation

Areas of Research:

We seek to quantitatively understand heat transfer, fluid flow and mass transfer during materials processing, particularly welding, chemical vapor deposition and metals processing. Much of our work involves numerical calculations of temperatures, velocities and concentrations using computers. The computed results provide detailed insight about the process and reveal how the composition and structure of the processed materials evolve. Our work focuses on overcoming two major problems of the current generation of models. First, the model predictions do not always agree with the experimental results because some process parameters or materials properties cannot be accurately prescribed. Second, and more important, these unidirectional models cannot determine multiple sets of process variables that can lead to a particular materials or process attribute. Our work shows that the computational convective heat and mass transfer models when combined with a genetic algorithm can overcome the aforementioned difficulties. The reliability of the models can be significantly improved by optimizing the values of the uncertain input parameters from a limited volume of experimental data. Furthermore, the procedure can calculate multiple sets of process variables, each leading to the same target materials or process attributes by conducting a global search within a phenomenological framework of the equations of conservation of mass, momentum and energy. This computational procedure was applied to gas tungsten arc welding of several alloys to calculate various sets of welding variables to achieve a specified weld geometry. Each set of welding parameters resulted in a specified geometry showing the effectiveness of the computational procedure.

Technology Impacted By Research:

Welding and joining
Thin films
Manufacture of iron and steel
Synthesis of composite materials

Journal Articles and Publications:

T. Hong, T. DebRoy, S. S. Babu, and S. A. David. 2000. “Modeling of Inclusion Growth and Dissolution in the Weld Pool.” Metallurgical and Materials Transactions 31B:161–169.
Z. Yang, J. W. Elmer, J. Wong, and T. DebRoy. 2000. “Evolution of Titanium Arc Weldment Macro- and Microstructures—Modeling and Real Time Mapping of Phases.” Welding Journal Research Supplement 79(4):97s–112s.
M. Pastor, H. Zhao, and T. DebRoy. 2000. “CW-Nd: YAG Laser Welding of AM60B Magnesium Alloy.” Journal of Laser Applications 12(3):91–100.
Z. Yang and T. DebRoy. 1999. “Modeling of Macro-and Microstructures of Gas-Metal-Arc Welded HSLA-100 Steel.” Metallurgical and Materials Transactions 30B:483–493.
H. Zhao, D. R. White, and T. DebRoy. 1999. “Current Issues and Problems in Laser Welding of Automo-tive Aluminum Alloys.” International Materials Reviews 44(6):238–266.

DebRoy

Long-Qing Chen

Long-Qing Chen
Distinguished Professor of Materials Science and Engineering
Materials Research Institute
N-321 Millennium Science Complex
(814) 863-8101
chen@matse.psu.edu
http://www.ems.psu.edu/~chen/

Biographical Sketch:

Long-Qing Chen is Distinguished Professor of Materials Science and Engineering and Professor of Engineering Science and Mechanics at the Pennsylvania State University. He is a short-term visiting Professor of Materials Science and Engineering at Tsinghua University under the short-term 1000-Scholar program, a guest Professor of Materials Science and Engineering at Zhejiang University, and a guest Professor of Physics at the Beijing University of Science and Technology in China. He received his B.S. degree in Materials Science and Engineering from Zhejiang University in China in 1982. After spending one year as an assistant instructor at Zhejiang University, he came to the United States in 1983 and received his M.S. degree in Materials Science and Engineering from the State University of New York at Stony Brook in 1985 and a Ph.D. degree in Materials Science and Engineering from the Massachusetts Institute of Technology (MIT) in 1990. After a two-year post-doc appointment with Professor Armen G. Khachaturyanat Rutgers University, he joined the faculty at Penn State as an Assistant Professor of Materials Science and Engineering in 1992. He was promoted to Associated Professor in 1998 and Professor in 2002. Professor Chen teaches undergraduate thermodynamics of materials and graduate kinetics of materials processes and also co-teaches one graduate course and one undergraduate course in computational materials science in the department. Professor Chen's main research interest is developing multiscale computational models for predicting microstructure evolution in materials using a combination of atomistic/first-principles calculations and phase-field methods. In particular, he is interested in microstructure evolution during phase transformations, grain growth, Ostwald ripening, ferroelectric and multiferroic domain switching, and coupled ionic/electronic transport in electrochemical systems. His research group collaborates actively with numerous experimental groups, applied mathematicians, and other fellow computational materials scientists and physicists as well as with more than a dozen companies and national labs. Professor Chen has published over 350 authored or co-authored papers (H-index = 51, Number of Citations >10,000), 1 patent licensed by Intel, and co-edited 3 books in the area of computational materials science of microstructures and properties. He has given more than 200 invited talks including 6 at the Gordon Research Conferences. Professor Chen's current and former graduate students have received more than 40 awards including Materials Research Society Graduate Student Gold and Silver Medal Awards, American Ceramic Society Graduate Excellence in Materials Science Awards, Acta Materialia best student paper award, Penn State Materials Research Institute best Ph.D. thesis research award, TMS Young Leader Award, etc. Professor Chen received numerous awards for his work including:

ONR Young Investigator Award (1995)
NSF special research creativity award (1999)
Wilson Award for Excellence in Research from his college (2000)
University Faculty Scholar Medal in Engineering at Penn State (2003)
Outstanding Overseas Young Scholar by the Chinese Natural Science Foundation (2004)
Changjiang Chair Professorship by the Chinese Ministry of Education (2004)
Guest Professor at Beijing University of Science and Technology (2004)
Guggenheim Fellow (2005)
Royal Society Kan Tong Po Fellowship at Hong Kong Polytechnic University (2005)
ASM Materials Research Silver Medal (2006)
American Physical Society Fellow (2008)
D. B. Robinson Distinguished Lecture at University of Alberta (2010)
Materials Science and Engineering Departmental Teaching Award of Students’ Choice (2010)
TMS EMPMD Distinguished Scientist/Engineer Award (2011)
Short-Term 1000-Talent Program Visiting Professorship at Tsinghua University (2011)
Bo Yugang Visiting Professorship at Zhejiang University (2012)
ASM Fellow (2012)
Penn State Distinguished Professorship (2013)
Materials Research Society (MRS) Fellow (2013)

Research Interests:

Computational materials science
Phase-field method
Multiscale modeling of microstructure evolution integrating first-principles calculations, and phase-field methods, and microstructure-property relationships
Phase transformations
Deformation twinning
Microstructure coarsening
Structural alloys (Ti-alloys, Ni-alloys, Al-alloys and Mg-alloys)
Domain structures in ferroelectric and magnetic materials, multiferroics
Electrochemical transport in dielectrics, batteries and solid oxide fuel cells.

Areas of Research:

Dr. Chen’s main research interest is in the fundamental understanding of the thermodynamics and kinetics of phase transformations and mesoscale microstructure evolution in bulk solid and thin films using computer simulations. Essentially all engineering materials contain certain types of microstructures, and our success of designing new materials is largely dependent on our ability to control them. Microstructure is a general term that refers to a spatial distribution of structural features that can be phases of different compositions and/or crystal structures, or grains of different orientations, or domains of different structural variants, or domains of different electrical or magnetic polarization, as well as structural defects such as dislocations. It is the size, shape, and spatial arrangement of the local structural features that determine the physical properties of a material such as mechanical, electrical, magnetic and optical properties. For the last decade, Dr. Chen’s group at Penn State is particularly active in developing phase-field models for microstructure evolution during various materials processes including grain growth, coherent precipitation, ferroelectric domain formation, particle coarsening, domain structure evolution in thin films, phase transformation in the presence of structural defects, and effect of stress on microstructure evolution. Current research focus is on the effect of stress/strain on ferroelectric phase transitions and domain structure evolution in ferroelectric and multiferroic thin films, domain structures in ferromagnetic shape memory alloys, electrode microstructure evolution in solid oxide fuel cells and batteries, precipitate microstructure evolution in Al-, Mg-, Ti- and Ni-alloys, strain-dominated morphological evolution, effect of defects such as dislocations on microstructure evolution. Dr. Chen’s group collaborates extensively with experimentalists and with industry.

Technology Impacted By Research:

Alloy development for aerospace and automobile iapplications
Ferroelectric and ferromagnetic thin films for memory, capacitor and electromechanical system applications
Solid oxide fuel cells and batteries

Journal Articles and Publications:

N. Balke, B. Winchester, W. Ren, Y. H. Chu, A. N. Morozovska, E. A. Eliseev, M. Huijben, R. K. Vasudevan, P. Maksymovych, J. Britson, S. Jesse, I. Kornev, R. Ramesh, L. Bellaiche, L. Q. Chen, and S. V. Kalinin, Enhanced electric conductivity at ferroelectric vortex cores in BiFeO3, Nature Physics, 2012. 8():p. 81-88
L.Y. Liang, Y. Qi, F. Xue, S. Bhattacharya, S.J. Harris, and L.Q. Chen, Nonlinear phase-field model for electrode-electrolyte interface evolution. Physical Review E, 2012. 86(5).
K. Chang, C.E. Krill, Q. Du, and L.Q. Chen, Evaluating microstructural parameters of three-dimensional grains generated by phase-field simulation or other voxel-based techniques. Modelling and Simulation in Materials Science and Engineering, 2012. 20(7).
B.S. Fromm, K. Chang, D.L. Mcdowell, L.Q. Chen, and H. Garmestani, Linking phase-field and finite-element modeling for process structure property relations of a Ni-base superalloy. Acta Materialia, 2012. 60(17): p. 5984-5999.
24. Y.H. Wen, L.Q. Chen, and J.A. Hawk, Phase-field modeling of corrosion kinetics under dual-oxidants. Modelling and Simulation in Materials Science and Engineering, 2012. 20(3).
H. Yang, S. Huang, X. Huang, F.F. Fan, W.T. Liang, X.H. Liu, L.Q. Chen, J.Y. Huang, J. Li, T. Zhu, and S.L. Zhang, Orientation-Dependent Interfacial Mobility Governs the Anisotropic Swelling in Lithiated Silicon Nanowires. Nano Letters, 2012. 12(4): p. 1953-1958.
J. M. Hu, Z. Li, L. Q. Chen, and C. W. Nan, High-density magnetoresistive random access memory operating at ultralow voltage at room temperature , Nature Communications, 2011. 2:Art. No. 553
T. W. Heo, S. Bhattacharyya, and L.Q. Chen, A phase field study of strain energy effects on solute-grain boundary interactions. Acta Materialia, 2011. 59(20): p. 7800-7815.
C. T. Nelson, B. Winchester, Y. Zhang, S.J. Kim, A. Melville, C. Adamo, C.M. Folkman, S.H. Baek, C.B. Eom, D.G. Schlom, L.Q. Chen, and X.Q. Pan, Spontaneous Vortex Nanodomain Arrays at Ferroelectric Heterointerfaces. Nano Letters, 2011. 11(2): p. 828-834.
S.H. Baek, H.W. Jang, C.M. Folkman, Y.L. Li, B. Winchester, J.X. Zhang, Q. He, Y.H. Chu, C.T. Nelson, M.S. Rzchowski, X.Q. Pan, R. Ramesh, L.Q. Chen, and C.B. Eom, Ferroelastic switching for nanoscale non-volatile magnetoelectric devices. Nature Materials, 2010. 9(4): p. 309-314.
R. J. Zeches, M.D. Rossell, J.X. Zhang, A.J. Hatt, Q. He, C.H. Yang, A. Kumar, C.H. Wang, A. Melville, C. Adamo, G. Sheng, Y.H. Chu, J.F. Ihlefeld, R. Erni, C. Ederer, V. Gopalan, L.Q. Chen, D.G. Schlom, N.A. Spaldin, L.W. Martin, and R. Ramesh, A Strain-Driven Morphotropic Phase Boundary in BiFeO3. Science, 2009. 326(5955): p. 977-980.
L. Q. Chen, Phase-field method of phase transitions/domain structures in ferroelectric thin films: A review. Journal of the American Ceramic Society, 2008. 91(6): p. 1835-1844.
D. G. Schlom, L.Q. Chen, C.B. Eom, K.M. Rabe, S.K. Streiffer, and J.M. Triscone, Strain tuning of ferroelectric thin films. Annual Review of Materials Research, 2007. 37: p. 589-626.
V. Vaithyanathan, C. Wolverton, and L.Q. Chen, Multiscale modeling of precipitate microstructure evolution. Physical Review Letters, 2002. 88(12).
L. Q. Chen, Phase-field models for microstructure evolution. Annual Review of Materials Research, 2002. 32: p. 113-140.

Chen