Emergence and Evolution of Crystallization in TiO₂ Thin Films: A Structural and Morphological Study

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Titanium dioxide (TiO2) is a versatile transition metal oxide with extensive applications.
• Understanding the amorphous-to-crystalline transition is crucial for optimizing TiO2-based devices.

Purpose of the Study:

• To investigate the crystallization onset and evolution in amorphous TiO2 thin films.
• To determine the influence of annealing temperature and film thickness on TiO2 crystallization.
• To explore the relationship between structural properties and phonon lifetime.

Main Methods:

• Amorphous TiO2 thin films produced via ion-plasma assisted e-beam deposition.
• Annealing treatments conducted from 250 °C to 1000 °C.
• Structural and morphological characterization using Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), and Raman spectroscopy.

Main Results:

• Crystallization onset temperature increases as TiO2 film thickness decreases.
• Significant variations in crystallization evolution observed based on film thickness.
• Complementary techniques revealed cross-talk, with surface imaging providing distinct crystallization insights.
• Phonon lifetime is affected by both TiO2 thickness and annealing temperature, correlating with crystallinity.

Conclusions:

• Film thickness is a critical parameter controlling TiO2 crystallization behavior.
• A combined approach using multiple characterization techniques offers comprehensive understanding of material transformations.
• The study provides insights into tuning TiO2 properties through controlled annealing and thickness variation.