9/25/2018  Our J. Appl. Phys. paper "Continuously variable atomic structure in monatomic metallic glasses through active icosahedral dynamics below glass transition temperature" is published online and exhibited as a featured article on the journal's homepage.

   

11/09/2018 Congratulations to Fangzheng on his first-author paper "3-D surface condensation of large atomic shear strain in nanoscale metallic glasses under low uniaxial stress" that has been accepted for publication in Journal of Physics: Condensed Matter.

 

1/9/2019 Fangzheng received his first review invitation from an excellent journal - he's starting to serve the international science community as a referee. 

1/2/2020 The world's largest copper based metallic glasses we developed in the past two years have been published by Applied Physics Letters today (https://aip.scitation.org/doi/10.1063/1.5131645). They possess the highest glass forming ability and processibility known to any copper-based glassy alloys, and yet are free of rare-earths, precious metals and toxic elements. Congratulations to Jaskaran (1st author) and Collin (2nd author) for making and testing the good alloys and to our co-authors who contributed some of the data presented in the paper. 

6/3/2020 The shell of an atomic cluster usually has higher potential energy than the core. But this is not the case for the 13-atom icosahedral clusters spontaneously formed in the supercooled-liquid and glassy states of pure metals. Our finding of the surprising core-shell ennergy-landscape inversion of the icosahedral clusters and its relation to the glass-forming ability of a metal has been accepted for publication in Journal of Physics: Condensed Matter.      (Figure: top row, icosahedral clusters in supercooled liquid Ta; lower row, BCC clusters in Ta metallic glass)

             

12/28/2020 Pure metals usually exist in simple crystal structures. Under special conditions (e.g. thin film deposition, ultrafast liquid quenching) they may be obtained in glassy or complex Frank-Kasper crystal forms. They may also be templated into a quasicrystal (QC) structure by epitaxial growth on a QC substrate. However, spontaneous formation of QC in a pure metal has not been reported. We have observed QC grains spontaneously formed in pure tantalum upon thermal annealing of a Ta metallic glass in molecular dynamics simulations. The work has been accepted for publication in AIP Advances.      (Figure: top row, QC grain and calculated electron diffraction pattern; lower row, beta-Ta -- a tetragonal FK phase)

04/16/2021 We thank Dr. Douglas Hofmann (NASA-JPL, 4/1), Prof. Jan Schroers (Yale University, 4/8) and Prof. William D. Nix (Stanford University, 4/15) for their impressive, informative and insightful presentations to our faculty and students through our MATSCI seminar series. Truly enjoyed and learned from your talks!    

6/18/2021 We have nearly doubled the current world record of critical casting thickness of hafnium (Hf) based bulk metallic glasses (HBMGs). HBMGs possess very high density (> 10 g/cc) and exceptional high-temperature wear-resistance, in addition to the common features (e.g., superhigh strength, hardness, wear- and corrosion-resistance, near net-shape castability) of metallic glasses, and are attractive material for kinetic energy penetrators and high performance gears and bearings. Previous civil and military (Navy and Army) efforts and investments over decades only resulted in a 3 mm (record of U.S.) or 10 mm (record of China) critical casting thickness. We have improved this record to 18 mm. Our paper has been published in Journal of Alloys and Compounds 882, 160896 (2021) (https://doi.org/10.1016/j.jallcom.2021.160896)

7/6/2022 Stacking fault tetrahedra (SFTs) are important vacancy defects in quenched, plastically deformed or irradiated FCC metals. Their formation mechanism and stability relative to 2-D vacancy loops are still debated. Equilateral hexagonal Frank loops (EHLs) observed in microscopy have been considered unable to transform to SFTs due to separation of Shockley partials. Thus, previously proposed mechanisms for SFT formation resorted to hypothetical triangular or scalene hexagonal Frank loops not substantiated by experiments. We have discovered direct transformation of EHLs to SFTs at elevated temperatures under thermal fluctuation through molecular dynamics simulations, which may put an end to the debate on the thermal origin of SFTs. This work has been accepted for publication in Journal of Physics: Condensed Matter after double-blind peer review.  (In the following figure: red atoms are HCP atoms -- atoms having an HCP environment; grey atoms are neither FCC nor HCP atoms; omitted in the background are FCC atoms)

7/28/2022 Icosahedral (ICO) clusters are known to exist in many supercooled metallic liquids and believed to play an important role in stabilizing the liquids before they transition into a glassy, crystalline or quasicrystalline solid. However, a detailed understanding of their formation energetics/dynamics is currently lacking and a set of key questions regarding these clusters remain to be answered, for example: Is the ICO cluster formation a thermally activated process? If so, why does the ICO population increase with decreasing temperature? If not, why is their population limited (and changing with temperature)? How is the formation energetics/dynamics of ICO clusters related to the potential energy landscape near the clusters? To answer these intriguing questions, we have studied the formation energetics/dynamics (including formation Gibbs free energy, entropy, enthalpy) of ICO clusters in liquid Cu64Zr36 and Ta by combining molecular dynamics simulations with statistical and theoretical analysis. Our paper has been published online today as an Invited Feature Paper (open access, free for both authors and readers) in the 2023 Early Career Scholars in Materials Science, a special issue of the Journal of Materials Research.   https://doi.org/10.1557/s43578-022-00664-5

8/5/2022 Congratulations to Jaskaran on passing his final defense and becoming a Doctor of Philosophy!

11/24/2022 Our group had great pleasure and honor hosting eight of our distinguished guests as speakers for the OSU Materials Science Seminars this fall: Prof. Mo Li (Georgia Tech), Prof. Frans Spaepen (Harvard Univ.), Prof. Olivier Delaire (Duke Univ.), Prof. Jamie Kruzic (UNSW Sydney), Prof. John Perepezko (Univ. Wisconsin - Madison), Prof. Brent Fultz (Caltech), Prof. Ju Li (MIT) and Prof. Ken Kelton (Washington Univ. in St. Louis). Thank you all for the wonderful talks!

3/15/2023 The PI finished the last lecture today for the most diverse MATS 555 class so far -- comprising 8 female and 3 male students who came from 9 different countries. Time for Boba tea and a class photo:

 

4/2/2023 The PI has designated chatGPT as a teaching/learning assistant for Mats 588 Computational Methods in Materials Science, while pointing out its insufficiency in physics and materials science and in coding/algorithms for complex materials science problems. 

5/18/2023 Madeline and Natasha presented our initial results of in-situ testing of Cu-Zr-Hf-Al metallic glasses at OSU's annual Celebrating Undergraduate Excellence (CUE) Showcase (2023). Our metallic glasses are four times as strong as steels! A 500 MPa stress makes steels flow like a plastic or a chewing gum, but it is almost nothing for our metallic glasses. (In the photo below, Left to Right: Madeline, Ploy - the PhD mentor, Natasha)

 

11/06/2023 The PI gave a seminar to the School of Materials Science and Engineering, Georgia Tech (GT). The presentation started with an introduction of the members and active projects of our group, and then focused on the experiments, modeling and simulations of crystal nucleation and growth in bulk and nano-sized metallic glasses. The PI appreciates the hospitality of all the GT faculty who spent time meeting with him. 

 

12/04/2023 Our new group asset - a pingpong table (paid through the PI's personal money) arrived today. Important to stay healthy while working hard! Learn table tennis from the GOAT (greatest of all time), Ma Long. 

  

1/19/2024 The PI is pleased to accept the invitation to be an Official Nominator for the prestigeous and highly valued VinFuture Prize. The VinFuture Prize is established to honor breakthrough scientific research and technological innovations that create meaningful change in the everyday lives of millions of people. The VinFuture Prize comprises:  1. A Grand Prize of US$3,000,000, awarded annually for breakthrough research and technological innovations that positively improve the quality of human life, and create a more equitable and sustainable world for future generations; 2. Three Special Prizes of US$500,000 each with a focus on promoting diversity, equity, and new fields of study awarded annually to: Innovators from Developing Countries; Female Innovators; Innovators with Outstanding Achievements in Emerging Fields. 

1/22/2024 Applied Physics Letters published our discovery of new amorphous Ti-Zr-Hf-Cu-Ni-Sn-Si alloys today (https://doi.org/10.1063/5.0191532). These alloys double the current world record of critical casting thickness for toxic-element (Be) and precious-metal free Ti-based bulk metallic glasses, while exhibiting simultaneous light weight, superhigh strength and specific strength, and good compressive plasticity. (all our record-breaking discoveries of new bulk metallic glasses are made purely by non-artificial Human Intelligence; AI, or AI designers, for complex materials discovery: long way to go)