LaAlO{sub 3} thickness window for electronically controlled magnetism at LaAlO{sub 3}/SrTiO{sub 3} heterointerfaces

Journal Article · Mon Aug 24 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4929430· OSTI ID:22489161

Bi, Feng; Huang, Mengchen; Irvin, Patrick; Levy, Jeremy ^[1]; Lee, Hyungwoo; Eom, Chang-Beom ^[2]

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1. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
2. Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

Complex-oxide heterostructures exhibit rich physical behavior such as emergent conductivity, superconductivity, and magnetism that are intriguing for scientific reasons as well as for potential technological applications. It was recently discovered that in-plane magnetism at the LaAlO{sub 3}/SrTiO{sub 3} (LAO/STO) interface can be electronically controlled at room temperature. Here, we employ magnetic force microscopy to investigate electronically controlled ferromagnetism at the LAO/STO interface with LAO thickness t varied from 4 unit cell (u.c.) to 40 u.c. Magnetic signatures are observed only within a thickness window 8 u.c. ≤ t ≤ 25 u.c. Within this window, the device capacitance corresponds well to the expected geometric value, while for thicknesses outside this window, the capacitance is strongly suppressed. The ability to modulate electronic and magnetic properties of LAO/STO devices depends on the ability to control carrier density, which is in turn constrained by intrinsic tunneling mechanisms.

• OSTI ID: 22489161
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 8 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINATES
ATOMIC FORCE MICROSCOPY
CAPACITANCE
CARRIER DENSITY
FERROMAGNETISM
LANTHANUM OXIDES
MAGNETIC FIELDS
MAGNETIC PROPERTIES
STRONTIUM TITANATES
SUPERCONDUCTIVITY
TEMPERATURE RANGE 0273-0400 K
THICKNESS
TUNNEL EFFECT