Growing clean crystals from dirty precursors: Solid-source metal-organic molecular beam epitaxy growth of superconducting Sr2RuO4 films
Abstract
Ultra-high purity elemental sources have long been considered a prerequisite for obtaining low impurity concentrations in compound semiconductors in the world of molecular beam epitaxy (MBE) since its inception in 1968. However, we demonstrate that a “dirty” solid precursor, ruthenium(III) acetylacetonate [also known as Ru(acac)3], can yield single-phase, epitaxial, and superconducting Sr2RuO4 films with the same ease and control as III–V MBE. A superconducting transition was observed at ∼0.9 K, suggesting a low defect density and a high degree of crystallinity in these films. In contrast to the conventional MBE, which employs the ultra-pure Ru metal evaporated at ∼2000 °C as a Ru source, along with reactive ozone to obtain Ru → Ru4+ oxidation, the use of the Ru(acac)3 precursor significantly simplifies the MBE process by lowering the temperature for Ru sublimation (less than 200 °C) and by eliminating the need for ozone. Combining these results with the recent developments in hybrid MBE, we argue that leveraging the precursor chemistry will be necessary to realize next-generation breakthroughs in the synthesis of atomically precise quantum materials.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 01, 2023
- Source ID
- 10.1063/5.0150893
Entities
People
- Bharat Jalan
- Jiaqi Cai
- Jiun-Haw Chu
- Rashmi Choudhary
- Xiaodong Xu
- Zhaoyu Liu
Organizations
- Air Force Office of Scientific Research
- National Science Foundation
- University of Minnesota
- University of Washington