238 research outputs found
Thermal switching of indirect interlayer exchange in magnetic multilayers
We propose a magnetic multilayer layout, in which the indirect exchange
coupling (IEC also known as RKKY) can be switched on and off by a slight change
in temperature. We demonstrate such on/off IEC switching in a Fe/Cr/FeCr-based
system and obtain thermal switching widths as small as 10--20~K, essentially in
any desired temperature range, including at or just above room temperature.
These results add a new dimension of tunable thermal control to IEC in magnetic
nanostructures, highly technological in terms of available materials and
operating physical regimes.Comment: 3 figures, Supplementary Inf
Ferromagnetic resonance and interlayer exchange coupling in magnetic multilayers with compositional gradients
Ferromagnetic resonance (FMR) in magnetic multilayers of type F1/f/F2, where
two strongly ferromagnetic layers F1 and F2 are separated by a weakly magnetic
spacer f with a compositional gradient along its thickness, is investigated.
The method allows to detect the weak signal from the spacer in additional to
the more pronounced and readily measured signal from the outer
strongly-magnetic layers, and thereby study the properties of the spacer as
well as the interlayer exchange interaction it mediates. Variable temperature
FMR measurements, especially near the relevant Curie points, reveal a rich set
of properties of the exchange interactions in the system. The obtained results
are useful for designing and optimizing nanostructures with
thermally-controlled magnetic properties.Comment: 6 pages, 3 figure
Guided Modes in the Plane Array of Optical Waveguides
It is known that for an isolated dielectric cylinder waveguide there exists
the cutoff frequency below which there is no guided mode. It is
shown in the paper that the infinite plane periodic array of such waveguides
possesses the guided modes in the frequency domain which is below the frequency
. In the case of a finite array, the modes in this frequency
domain are weakly radiating ones, but their quality factor increases with
the number of waveguides as . This dependence is obtained
both numerically, using the multiple scattering formalism, and is justified
with a simple analytical model
- …