Related Experiment Video
Updated: May 3, 2026
09:41
Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
Published on: May 29, 2018
8.8K
Emergent spin filter at the interface between ferromagnetic and insulating layered oxides.
Yaohua Liu1, F A Cuellar2, Z Sefrioui2
1Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Physical Review Letters
|February 4, 2014
Summary
We observed an unusual drop in tunnel magnetoresistance at low temperatures in magnetic tunnel junctions. This behavior stems from competing magnetic effects at the interface between La0.7Ca0.3MnO3 and PrBa2Cu3O7.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Magnetic tunnel junctions (MTJs) are crucial for spintronic devices.
- Understanding interface effects is key to controlling MTJ properties.
- La0.7Ca0.3MnO3 (LCMO) and PrBa2Cu3O7 (PBCO) are complex oxides with interesting magnetic and electronic properties.
Purpose of the Study:
- To investigate the transport properties of MTJs composed of LCMO and PBCO.
- To explore the influence of interface-induced magnetization on tunnel magnetoresistance (TMR).
- To elucidate the mechanism behind anomalous TMR behavior at low temperatures.
Main Methods:
- Fabrication of MTJs using ferromagnetic LCMO and insulating PBCO layers.
- Measurement of TMR as a function of temperature.
- Analysis of the interplay between manganite spin polarization and interface magnetism.
Main Results:
- Observed a strong effect of interface-induced magnetization on MTJ transport.
- Contrary to expectations, TMR showed an anomalous decrease at low temperatures.
- The anomalous behavior was linked to competing magnetic interactions at the LCMO-PBCO interface.
Conclusions:
- Interface-induced magnetism significantly alters MTJ transport properties.
- A novel low-temperature TMR anomaly was discovered in this system.
- The findings highlight the complex interplay of spin polarization and interface effects in oxide heterostructures.
Related Concept Videos
02:42Valence Bond Theory
8.9K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.9K
01:31Ferromagnetism
2.8K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.8K
01:28Magnetostatic Boundary Conditions
1.9K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.9K
03:02Colors and Magnetism
12.1K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.1K
01:26Diamagnetism
2.8K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.8K
01:31Magnetic Susceptibility and Permeability
2.9K
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
2.9K