Magnetic properties and interfacial phenomena of epitaxial perovskite oxides depend sensitively on parameters such as film thickness and strain state. In this work, epitaxial La 0.67 Sr 0.33 CoO 3 (LSCO)/La 0.67 Sr 0.33 MnO 3 (LSMO) bilayers were grown on NdGaO 3 (NGO) and LaAlO 3 (LAO) substrates with a fixed LSMO thickness of 6 nm, and LSCO thickness (t LSCO ) varying from 2 to 10 nm. Soft x-ray magnetic spectroscopy revealed that magnetically active Co 2+ ions that strongly coupled to the LSMO layer were observed below a critical t LSCO for bilayers grown on both substrates. On LAO substrates, this critical thickness was 2 nm, above which the formation of Co 2+ ions was quickly suppressed leaving only a soft LSCO layer with mixed valence Co 3+ /Co 4+ ions. The magnetic properties of both LSCO and LSMO layers displayed strong t LSCO dependence. This critical t LSCO increased to 4 nm on NGO substrates, and the magnetic properties of only the LSCO layer displayed t LSCO dependence. A non-magnetic layer characterized by Co 3+ ions and with a thickness below 2 nm exists at the LSCO/substrate interface for both substrates. The results contribute to the understanding of interfacial exchange spring behavior needed for applications in next generation spintronic and magnetic memory devices.
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Role of Lithium Doping in P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 for Sodium-Ion Batteries
- Award ID(s):
- 1834750
- NSF-PAR ID:
- 10409616
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Chemistry of Materials
- Volume:
- 33
- Issue:
- 12
- ISSN:
- 0897-4756
- Page Range / eLocation ID:
- p. 4445-4455
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
