In-Situ Analysis

Thermally Stable Au-BaTiO3 Nanoscale Hybrid Metamaterial for High Temperature Plasmonic Applications

D. Zhang, Z. Qi, J. Jian, J. Huang, X. Phuah, X. Zhang, H. Wang, ACS Applied Nano Materials, 3(2): 1431-1437, (2020).

Highlights:

  • Robust thermal stability of BaTiO3-Au (oxide-metal) VAN thin film demonstrated via ex situ XRD, TEM and in situ TEM heating.

  • Stable optical properties at high temperature including localized surface plasmon resonance and hyperbolic dispersion.

Direct observation of Lomer-Cottrell Locks during strain hardening in nanocrystalline nickel by in situ TEM

J.H. Lee, T.B. Holland, A.K. Mukherjee, X. Zhang, H. Wang, Scientific Reports, 3, (2012).

Highlights:

  • Direct observation of dynamic work hardening event in nanocrystalline nickel by in situ transmission electron microscope nanoindentations.

  • Abundant Lomer-Cottrell (L-C) locks formed both within nanograins and against twin boundaries during strain hardening stage.

  • L-C locks formed within grains were removed at higher stress by mobile dislocations.

  • L-C locks when encountered twin boundaries can lead to even greater work hardening.

Direct observation of twin deformation in YBa2Cu3O7-x thin films by in situ nanoindentation in TEM

J.H. Lee, X. Zhang, H. Wang, Journal of Applied Physics, 109, 083510, (2011).

Highlights:

  • The hardness measured perpendicular to the twin interfaces is .40% higher than that measured parallel to the twin interfaces by in situ TEM nanoindentations.

  • During deformation, a certain portion of the twin structures reversed contrast and variations of the width of twin boundaries were observed during the loading and unloading process.

Grain and grain boundary activities observed in alumina–zirconia–magnesia spinel nanocomposites by in situ nanoindentation using transmission electron microscopy

J.H. Lee, I. Kim, D.M. Hulbert, D. Jiang, A.K. Mukherjee, X. Zhang, H. Wang, Acta Materialia, 58, 4891-4899, (2010).

Highlights:

  • The Al2O3:ZrO2:MgAl2O4 (AZM) nanocomposites undergo the deformation mainly through the grain-boundary sliding and rotation of small grains, i.e. ZrO2 grains, and some of the large grains, i.e. MgAl2O4 grains.

  • Both plastic and elastic deformations were observed in different sample regions at room temperature.

  • In certain areas where several large grains (Al2O3 and MgAl2O4) were surrounded by many small grains (ZrO2), the region mainly went through elastic deformation due to the strong grain activities in the small ZrO2 grains.

  • In other regions where mainly the hard Al2O3 and soft MgAl2O4 grains exist, a certain amount of plastic deformation was observed and the grains undergo a series of grain rotation, grain boundary sliding, and realignment.