3 research outputs found
Disentangling magnetic hardening and molecular spin chain contributions to exchange bias in ferromagnet/molecule bilayers
We performed SQUID and FMR magnetometry experiments to clarify the
relationship between two reported magnetic exchange effects arising from
interfacial spin-polarized charge transfer within ferromagnetic metal
(FM)/molecule bilayers: the magnetic hardening effect, and
spinterface-stabilized molecular spin chains. To disentangle these effects,
both of which can affect the FM magnetization reversal, we tuned the metal
phthalocyanine molecule central site's magnetic moment to selectively enhance
or suppress the formation of spin chains within the molecular film. We find
that both effects are distinct, and additive. In the process, we 1) extended
the list of FM/molecule candidate pairs that are known to generate magnetic
exchange effects, 2) experimentally confirmed the predicted increase in
anisotropy upon molecular adsorption; and 3) showed that spin chains within the
molecular film can enhance magnetic exchange. This magnetic ordering within the
organic layer implies a structural ordering. Thus, by distengangling the
magnetic hardening and exchange bias contributions, our results confirm, as an
echo to progress regarding inorganic spintronic tunnelling, that the milestone
of spintronic tunnelling across structurally ordered organic barriers has been
reached through previous magnetotransport experiments. This paves the way for
solid-state devices studies that exploit the quantum physical properties of
spin chains, notably through external stimuli.Comment: Non
Spin-Dependent Hybridization between Molecule and Metal at Room Temperature through Interlayer Exchange Coupling
We
experimentally and theoretically show that the magnetic coupling at
room temperature between paramagnetic Mn within manganese phthalocyanine
molecules and a Co layer persists when separated by a Cu spacer. The
moleculeâs magnetization amplitude and direction can be tuned
by varying the Cuâspacer thickness and evolves according to
an interlayer exchange coupling mechanism. <i>Ab initio</i> calculations predict a highly spin-polarized density of states at
the Fermi level of this metal-molecule interface, thereby strengthening
prospective spintronics applications
High Spin Polarization at Ferromagnetic MetalâOrganic Interfaces: A Generic Property
A high
spin polarization of states around the Fermi level, <i>E</i><sub>F</sub>, at room temperature has been measured in
the past at the interface between a few molecular candidates and the
ferromagnetic metal Co. Is this promising property for spintronics
limited to these candidates? Previous reports suggested that certain
conditions, such as strong ferromagnetism, i.e., a fully occupied
spin-up d band of the ferromagnet, or the presence of Ï bonds
on the molecule, i.e., molecular conjugation, needed to be met. What
rules govern the presence of this property? We have performed spin-resolved
photoemission spectroscopy measurements on a variety of such interfaces.
We find that this property is robust against changes to the molecule
and ferromagnetic metalâs electronic properties, including
the aforementioned conditions. This affirms the generality of highly
spin-polarized states at the interface between a ferromagnetic metal
and a molecule and augurs bright prospects toward integrating these
interfaces within organic spintronic devices