Novel Complex Intermetallic Compounds (Single Crystals)

(Current Sponsor: NASA Early Career)

 

Novel complex intermetallic compounds are known to possess unique chemical, electronic, physical, and magnetic properties. Their special atomic arrangements usually lead to interesting mechanical behaviors. In this project, we use (1) solution growth, (2) nanofabrication, (3) nanomechanical tests, and (4) advanced computer simulations (DD, MD, DFT) for fundamental understanding of mechanical behavior of novel intermetallic compounds.

Solution growth method is an excellent way to grow various kinds of single crystalline metallic compounds with a millimeter length scale, compared to Bridgman or Czochralski methods. Thus, this growth method is adequate for academic studies. With the right choice of composition and temperature (based on a phase diagram), a single crystalline intermetallic compound can be grown in a high temperature solution, and can be extracted by rapid decanting process. Then, focused-ion-beam (FIB) milling is used to fabricate nano-/micro-pillar with different sizes and orientations for nanomechanical tests. Both ex-situ and in-situ nano-nanoindentation systems are used to obtain stress-strain data and to understand their mechanical behavior at small length scales. Advanced computation simulations are also used to understand the details of deformation mechanisms.

Collaboration Efforts

 

< Solution Growth of Single-Crystalline Intermetallic Compound >

Screen Shot 2016-01-10 at 8.16.32 PM

Please enjoy Prof. Paul Canfield (Physics, Iowa State Univ)’s excellent description of solution growth of single crystals.

(1) Solution growth of intermetallic compounds: A Beginner’s Guide

(2) Design and Growth of Novel Materials

<Photos of some intermetallic compound single crystals>

 

<Giant Superelasticity of [0 0 1] CaFe2As2>

This intermetallic compound exhibits ~14% of elastic strain under compression through reversible phase transition between tetragonal and collapsed tetragonal phases at room temperature.

(John T. Sypek et al., “Superelasticity and cryogenic linear shape memory effects in CaFe2As2,” Nature Communications 8 1083 (2017))

<Giant Superelasticity of [0 0 1] CaKFe4As4>

This intermetallic compound exhibits ~17% of elastic strain under compression through reversible phase transition between tetragonal and half-collapsed tetragonal phases at room temperature.

(Gyuho Song, et al., “Ultrahigh elastically compressible and strain-engineerable intermetallic compounds under uni-axial mechanical loading,” APL Materials 7, 061104 (2019))

 

Related Publications

  • Ian N. Bakst, John T. Sypek, Sriram Vijayan, Shuyang Xiao, Mark Aindow, Seok-Woo Lee, Christopher R. Weinberger ,”Uniaxial compression of CaFe2As2 single crystals: the effects of microstructure and temperature on superelasticity – Part II: ModelingActa Materialia, 203, 116462 (2021) [PDF][web]
  • John T. Sypek, Sriram Vijayan, Ian N. Bakst, Shuyang Xiao, Matthew J. Kramer, Paul C. Canfield, Mark Aindow, Christopher R. Weinberger, Seok-Woo Lee, “Uniaxial compression of CaFe2As2 single crystals: the effects of microstructure and temperature on superelasticity – Part I: Experimental ObservationActa Materialia, 203, 116464 (2021) [PDF][web]
  • Gyuho Song, Vladislav Borisov, William R. Meier, Mingyu Xu, Keith J. Dusoe, John T. Sypek, Roser Valenti, Paul C. Canfield, Seok-Woo Lee*, “Ultrahigh elastically compressible and strain-engineerable intermetallic compounds under uni-axial mechanical loading,” APL Materials 7, 061104 (2019) [PDF] [web]
  • Keara Frawley, Ian Bakst, John T. Sypek, Sriram Vijayan, Christopher R. Weinberger, Paul C. Canfield, Mark Aindow, Seok-Woo Lee, “A nanoindentation study on plastic deformation and fracture behaviors of [0 0 1] CaFe2As2 intermetallic compound,” JOM 70, 1074-1080 (2018) [PDF][web]
  • Ian N. Bakst, John T. Sypek, Seok-Woo Lee, James R. Neilson, Christopher R. Weinberger, “Modeling pseudo-elastic behavior in small-scale ThCr2Si2-type crystals,” – Computational Materials Science 150, 86-95 (2018) [PDF][web]
  • Ian N. Bakst, Keith J. Dusoe, Gil Drachuk, James R. Neilson, Paul C. Canfield, Seok-Woo Lee, Christopher R. Weinberger, “Effects of point defects on the mechanical response of LaRu2P2,” Acta Materialia 160 224-234 (2018) – [PDF][web]
  • John T. Sypek, Hang Yu, Keith J. Dusoe, Gil Drachuck, Hetal Petal, Amanda M. Giroux, Alan I. Goldman, Andreas Kreyssig, Paul C. Canfield, Sergey L. Bud’ko, Christopher R. Weinberger, Seok-Woo Lee, “Superelasticity and cryogenic linear shape memory effects of CaFe2As2,Nature Communications 8 1083 (2017) [PDF][web]
  • John T. Sypek, Christopher R. Weinberger, Sriram Vijayan, Mark Aindow, Paul C. Canfield, Seok-Woo Lee, “Superealstic and micaceous deformation in the intermetallic compound CaFe2As2,” Scripta Materialia 141 10-14 (2017) – [PDF][web]