- Msepostdoc-list - ecn.purdue.edu

2 Seminars this Friday, Professor Lihua Qian and Dr. Voramon Dheeradhada
by Coar, Stacey L 24 Apr '19

24 Apr '19

[cid:image002.png@01D4FA72.3DF725D0] [cid:image001.png@01D4FA72.1BCCA840] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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REMINDER TODAY: MSE 690 Seminar Speaker - Don Brown, Ph.D., Monday, April 22, 2019/ARMS 1010 - 3:30
by Coar, Stacey L 22 Apr '19

22 Apr '19

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MSE 690 Seminar Speaker - Don Brown, Ph.D., Monday, April 22, 2019/ARMS 1010 - 3:30
by Coar, Stacey L 19 Apr '19

19 Apr '19

Please join us Monday, April 22nd, to see Don Brown from Los Alamos speak in MSE 690 at 3:45. Thank you, Stacey [cid:image002.png@01D4F68C.1E526E40]

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Seminar Notice for Yang Wang's Preliminary Exam Friday, April 26, at 10:30 a.m., in HAMP G212. "MOCVD Growth of 1.8 eV Band Gap Zinc Oxide Materials for Solar Cell Applications"
by Son, Rosemary E 19 Apr '19

19 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "MOCVD Growth of 1.8 eV Band Gap Zinc Oxide Materials for Solar Cell Applications" By Yang Wang Purdue MSE Preliminary Exam Advisors: Professor Na Lu and Professor Haiyan Wang ABSTRACT Zinc oxide (ZnO) is of great research and application interest as a wide band-gap semiconductor in recent years. It has many desired properties for photovoltaic, thermoelectric and optoelectronic applications, such as large and direct bandgap, high exciton binding energy, earth abundancy, large Seebeck coefficient, high thermal stability, and availability of various nanostructures, nontoxic, etc. This thesis research aims to develop 1.8 eV bandgap semiconductor materials with earth-abundant element Zn using Metal Organic Chemical Vapor Deposition (MOCVD) method. These materials serve as topping layer of a multi-junction solar cell which is a combination of 1.8 eV wide bandgap Schottky solar cell on a 1.1eV band gap Si solar cell to reach high power conversion efficiency at relatively low cost using sustainable and non-toxic materials. Preliminary results show that Ni alloying can tune the bandgap of ZnO in relatively large range. The lowest bandgap achieved in as-grown NiZnO films is 2.0 eV and the band gap is further reduced to 1.83 eV after post annealing. It is expected that the outcome of the work will facilitate the fabrication and manufacture of low-cost wide band gap material with broad band gap tunability for solar cell and other applications. Date: Friday, April 26, 2019 Time: 10:30 A.M. Place: HAMP G212

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Seminar Reminder for Kayla Yano's Ph.D. Final Exam. Seminar Thursday, April 18, at 9:00 a.m., in ARMS 3115. Exam same day in ARMS 2326, at 10:00 a.m. "In Situ TEM Mechanical Testing in Irradiated Oxide Dispersion Strengthened Alloys"
by Son, Rosemary E 17 Apr '19

17 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "In Situ TEM Mechanical Testing in Irradiated Oxide Dispersion Strengthened Alloys" By Kayla H. Yano Purdue MSE Ph.D. Final Exam Advisors: Professor Janelle P. Wharry and Professor Maria Okuniewski ABSTRACT The objective of this dissertation is to demonstrate the use of in situ TEM mechanical testing to find mechanical properties of as received, self-ion, and proton irradiated Fe-9%Cr ODS. The use of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers. Yet at such small micron or nanometer scales the mechanical properties can begin to be impacted by size-effects. In this work micropillar compression, cantilever bending, lamellae indentation, and clamped beam fracture testing is conducted on ion-irradiated Fe-9%Cr ODS to find yield stress, elastic modulus, flow stress, and fracture toughness. We find a threshold in sample dimension at which size-effects are observed that is directly related to obstacle spacing. By combining an understanding of the microstructure of irradiated Fe-9%Cr ODS and the in situ TEM technique, one can find the bulk-like mechanical properties of ion irradiated Fe-9%Cr ODS. Date: Thursday, April 18, 2019 Time: 9:00 A.M. Place: ARMS 3115

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MSE Merchandise Last Chance Closing Today!
by Coar, Stacey L 17 Apr '19

17 Apr '19

Hello Everyone, This is a reminder that the online MSE store will close tonight, April 17th at Midnight. PUMA is selling a short sleeve T-shirt, long sleeve T-shirt, 1/4 zip pullover, and two types of School of Materials Engineering polos. As I said before I will send an email when the shirts are ready to be picked up from Stacey, if you selected that delivery option, which should be around April 25th. Here is the link to the Freckles Online Store: https://shop.frecklesgraphics.com/purdue_materials_science_and_en/shop/home [https://images.inksoft.com/images/publishers/563/stores/purdue_materials_sc…]<https://shop.frecklesgraphics.com/purdue_materials_science_and_en/shop/home> Purdue Materials Science and Engineering<https://shop.frecklesgraphics.com/purdue_materials_science_and_en/shop/home> shop.frecklesgraphics.com Thank You, Harley Rowland PUMA Treasurer hrowlan(a)purdue.edu<mailto:hrowlan@purdue.edu> 832-922-9108

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FW: Seminar Notice for Kyungjean Min's Ph.D. Final Exam. Seminar, Wednesday, April 17, at 1:30 p.m., in ARMS 1021. Exam same day at 2:30 p.m., in ARMS 2009. "Impurity Control and Analysis of Ultra-Pure Gallium for Increasing Mobility in Gallium Arsenide G
by Son, Rosemary E 16 Apr '19

16 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Impurity Control and Analysis of Ultra-Pure Gallium for Increasing Mobility in Gallium Arsenide Grown by Molecular Beam Epitaxy" By Kyungjean Min Purdue MSE Ph.D. Final Exam Advisor: Professor Kevin P. Trumble and David R. Johnson ABSTRACT High mobility 2DEG (two-dimensional electron gas) confined in GaAs is a good platform to understand correlated electron systems and a promising candidate for qubit devices. For example, the non-Abelian feature of Fractional Quantum Hall state enabling topological quantum computation is only found in GaAs with high mobility. Theoretical calculations have shown that the mobility is inversely proportional to impurities in GaAs/AlGaAs heterstructures grown by Molecular Beam Epitaxy (MBE). In recent MBE experiments, the source Ga was found to be more important in the limitation of mobility than Al and As. A high mobility of 35 million cm2/Vs was recently observed when an 8N Ga (total nominal impurity concentration of ~10 ppb) source was used compared to 25 million cm2/Vs for a 7N Ga source. In addition, significant mobility increase was observed after in-situ distillation of the source Ga before growth. In order to clarify the mechanism of how the distillation contributed to the Ga purification, thus resulting the mobility increase, the MBE in-situ distillation was analyzed by molecular distillation theory. Evaporation behavior of solvent Ga was analyzed including effects of evaporation from a crucible with receding liquid depth. Then impurity removal through molecular distillation was analyzed with molecular evaporation kinetics. The remaining 7N and 8N Ga after in-situ MBE distillation and growth were elementally analyzed by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and compared with analyses of the starting 7N and 8N Ga from same lots. Due to the increased detection limit of ICP-MS in metal analysis, the concentrations of most impurity elements reached the detection limit of ~1-10 ppb. However, unusual high concentration of 690 ppb Ge was found in the 7N Ga, exceeding the nominal concentration of 7N (100 ppb). Significant decrease in Ge concentration was found in the comparison of initial ultra-pure Ga and remaining Ga for both grades of 7N and 8N. The significant Ge losses cannot be explained by atomic Ge evaporation due to the low vapor pressure of Ge. However, a hypothesis Ge evaporation as GeO(g) by Ge active oxidation was proposed. In order to test the active oxidation of very dilute Ge in Ga in the MBE conditions with very low P(O2), the equilibrium P(GeO)-P(O2) vapor species diagram was calculated from thermodynamics. The analysis shows that even very dilute Ge in Ga of ~ 1 ppm concentration can be actively oxidized in the extremely low P(O2) of MBE. In order to prove active oxidation of Ge, molecular distillation of 7N Ga was performed in a specially constructed high vacuum chamber. The 7N Ga with unusual high Ge concentration of 440 ppb (by GDMS analysis) was distilled for 16 h at 1360 K under the starting P(O2) of 3 x 10-6 atm and the total pressure of ~ 10-5 torr. The chamber vacuum was monitored by Residual Gas Analyzer (RGA) and the residual Ga after 16 h distillation was analyzed by GDMS. In the GDMS analysis, significant Ge loss was found from 440 ppb to below the detection limit of 10 ppb, confirming Ge active oxidation hypothesis. The oxygen-assisted impurity removal in distillation also may be applicable to other impurities with high vapor pressure gaseous oxide, but low vapor pressure itself such as Al, Si and Sn. Date: Wednesday, April 17, 2019 Time: 1:30 P.M. Place: ARMS 1021

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Seminar Reminder for Eduard Caicedo-Casso's Ph.D. Final Exam. Wednesday, April 17, in HAMP 2113, at 3:00 p.m. Exam same day, in ARMS 2237, at 4:00 p.m. " Shear Rheometry Protocols to Advance the Development of Microstructured Fluids"
by Son, Rosemary E 16 Apr '19

16 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Shear Rheometry Protocols to Advance the Development of Microstructured Fluids" By Eduard A. Caicedo-Casso Purdue MSE Ph.D. Final Exam Advisor: Professor Kendra A. Erk ABSTRACT The successful transformation of microstructured (complex) fluids into commercial products often relies on the ability to understand and control their rheological behavior. However, the implementation of rheological frameworks to drive business decisions is challenging. Majority of these fluids contain a wide variety of mesoscopic phases that contribute to a convoluted and distinct rheological response. Therefore, it is essential to combine flow characterization techniques with proper physical measurements to fully elucidate the root causes of the rheological behavior of microstructured fluids. In this order of ideas, this doctoral dissertation shows the development of three protocols of applied shear rheology. These protocols aim to advance the transformation of novel self-assembly block copolymers, concentrated surfactant solutions, and water-soluble polymers into real products. A robust set of experimental evidence is used to bridge the mesoscopic signatures of each microstructured fluid to their flow behavior. This talk focuses on the demonstration of the critical factors (chemical, physical, or thermodynamical) that could potentially drive the rheological behavior thus the successful transformation of the studied microstructured fluids. The novelty of this work lies in the integration of simple rheological measurements, scattering characterization techniques, mass transfer measurements, and advanced rheo-flow velocimetry to draw meaningful conclusions relevant to current industrial demands Date: Wednesday, April 17, 2019 Time: 3:00 P.M. Place: HAMP 2113

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Seminar Notice for Brenden Hamilton's Preliminary Exam Seminar. Thursday, April 25, at 10:30 a.m., in ARMS 3115. " Equilibrium Shock Approximation Methods and Their Applicability to Simulate Complex Shock Induced Phenomenon"
by Son, Rosemary E 16 Apr '19

16 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Equilibrium Shock Approximation Methods and Their Applicability to Simulate Complex Shock Induced Phenomenon" By Brenden W. Hamilton Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Alejandro Strachan ABSTRACT The thermo-mechanical and chemical response of materials under shock loading conditions is an important area of research for metallurgy, energetic materials, chemistry, geoscience, and astrophysics. Both experimental and theoretical research has focused on the role of shock in inducing phenomenon such as plasticity, phase transformation, failure, and chemical reactions. Due to the ultrafast timescales of these phenomena, molecular dynamics (MD) simulations are widely used to study shock. However, non-equilibrium, direct shock simulations are limited by the achievable length and time scales, with many shock-induced phenomena occurring on longer timescales than are achievable. This work aims to compare two computational approaches to simulate a material under shock loading conditions behind the shock front: The Multi-Scale Shock Technique (MSST) and the Hugoniostat. The former is derived from an extended Lagrangian with a shock pressure determined from the Rankine-Hugoniot Jump Conditions, confining the system to states along the Rayleigh Line (single shock velocity). The latter approach employs coupled volume and heat flow equations of motion that dynamically compresses the system to a desired shock pressure while varying energy to conserve the jump conditions. Both methods will be compared using the underlying theory as well as with complex test cases. Simulations are conducted for the energetic material TATB to compare shock induced volume expanding reactions to Zel'dovich-von Neumann-Döring Theory (ZND). Additionally, shock induced densification of the highly porous metal-organic framework MOF5 will be studied and compared to non-equilibrium shock simulations. Date: Thursday, April 25, 2019 Time: 10:30 A.M. Place: ARMS 3115

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LAST CHANCE: MSE Student Night April 25, 2019, Please Respond
by Coar, Stacey L 15 Apr '19

15 Apr '19

Good morning, Student night is just around the corner, this is your last chance to sign up for MSE Student Night on April 25th from 6:30 – 8pm. This event is a great opportunity to network with your peers, industry professionals, faculty and staff, and food will be provided. This is also a great opportunity to see this year’s senior design posters and the press boxes at Ross-Ade! RSVP at MSE student night 2019 survey<https://purdue.ca1.qualtrics.com/jfe/form/SV_bHkvgdmw35UcSI5> by this Friday, April 19th if you have not taken the survey. Important Info: · RSVPS are required (even for seniors) · Business attire, photos will be taken with Sponsors · Student and Faculty award presentations will be presented during the program [cid:image001.jpg@01D4F374.0ACE86D0] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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