In situ synchrotron radiation-based structural characterization of core-shell heterostructured phase transition oxides

Research Summary

Manipulation of physical properties through stress engineering is an important issue for the use of ultrafast metal-insulator transition (MIT) in device applications based on strongly correlated vanadium dioxide (VO₂). Recent research efforts have mainly focused on modulation and related phenomena of physical properties by epitaxial and mechanical stresses in VO₂ films or anisotropic nanocrystals. However, inhomogeneous stress in such planar and nanocrystal systems leads to complications induced by phase competitions or the creation of intermediate phases. Core-shell structures can enhance the ability to control and modulate stress, and thus electronic and optical properties. In this work, we demonstrated the core-shell heterostructure-enabled stress engineering on MIT using in situ synchrotron radiation-based structural characterization, combining with the finite element analyses of stress states in core-shell heterostructured VO₂ (CS-VO₂) and pristine VO₂ nanobeams.

Expected Outcomes

This result can lead to better engineering of phase transitions in SCMs for electronic, opto-electronic, and photonic device applications and can be used to develop in situ synchrotron radiation-based characterization tools.

Related Figures

• [Figure 1] In situ synchrotron radiation-based structural characterization
• [Figure 2] Stress-temperature phase diagram, temperature-dependent resistance change, and TEM results