Adsorption-Controlled Growth and Magnetism in Epitaxial SrRuO₃ Films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Thin Film Growth

Background:

• Defect control in strontium ruthenium oxide (SrRuO3) films is crucial for understanding structure-property relationships.
• SrRuO3 exhibits complex electrical and magnetic behaviors influenced by its stoichiometry and crystalline structure.

Purpose of the Study:

• To demonstrate adsorption-controlled growth of phase-pure, epitaxial, and stoichiometric SrRuO3 films.
• To investigate the origins of anomalous Hall effect features in SrRuO3 films.
• To achieve high-quality SrRuO3 films with enhanced electrical transport properties.

Main Methods:

• Solid source metal-organic molecular beam epitaxy (MOMBE) for film growth.
• Electrical transport measurements to analyze resistivity and anomalous Hall effect.
• Magnetometry to characterize magnetic domains and their influence on electrical properties.

Main Results:

• Phase-pure, epitaxial, and stoichiometric SrRuO3 films were grown on SrTiO3 (001) substrates via adsorption control.
• Anomalous Hall curves were attributed to distinct magnetic domain structures with varying polarities.
• A record residual resistivity ratio (RRR) of 87 was achieved for a 50 nm-thick, strained, stoichiometric SrRuO3 film.

Conclusions:

• Adsorption-controlled MOMBE is effective for producing high-quality SrRuO3 films.
• Understanding magnetic domain contributions is vital for interpreting electrical transport in SrRuO3.
• Strain engineering offers a pathway for further improving SrRuO3 film quality and properties.