superlattices: Tunable ferromagnetic insulator
- Hanyang Univ., Seoul (Korea, Republic of). Dept. of Physics
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sungkyunkwan Univ., Suwon (Republic of Korea). Dept. of Physics
Ferromagnetic insulators have great potential for spintronic applications. For such applications, it is essential to find materials with a robust and controllable ferromagnetic insulating phase. Yet, because ferromagnetism in functional transition-metal oxides is usually coupled to metallicity, ferromagnetic insulators are very rare and independent control of their magnetic and electrical properties is difficult. In this study, the electrical, magnetic, and optical properties of (LaCoO3)n/(SrCoO2.5)n superlattice films are investigated for the manipulation of the ferromagnetic insulating phase. While the superlattices remain insulating irrespective of the periodicity n, the electronic structure and magnetic state vary drastically. Superlattices with large periodicities n of 10 and 20 show a ferromagnetic transition at a critical temperature TC of ~80K. With decreasing periodicity and increasing interface density of the superlattices, system with n=4 becomes almost nonmagnetic, while in systems with n=2 and 1, a reentrant ferromagnetic phase is observed at TC of ~180 and ~225K, respectively. Optical spectroscopy reveals that the fine control of the magnetic ground state is achieved by the modified electronic structure associated with the spin-state transition. Our findings indicate an important design principle to create and manipulate the ferromagnetic insulating properties of Co-based oxide thin films.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; Ministry of Science, ICT and Future Planning; USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1561652
- Alternate ID(s):
- OSTI ID: 1558702
- Journal Information:
- Physical Review B, Vol. 100, Issue 6; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Strain-induced majority carrier inversion in ferromagnetic epitaxial thin films
Evolution of magnetism in single-crystal