We study the magnetocaloric effect in layered systems composed of a ferromagnet with a relatively low Curie temperature (TC), which is sandwiched by stronger ferromagnets and exchange coupled to them across the interfaces. Switching of magnetization in the softer ferromagnetic surrounding in an applied magnetic field (H) of the strength in several tens of oersteds provides the isothermal magnetic entropy change (Δs) in the system because of magnetization redistribution in the spacer. Our simulations of these effects we present here reveal the maximal value of Δs, obtained at a realistic interfacial exchange constant, which is in quantitative agreement with this quantity observed experimentally in different heterosystems based on the NixCu100 − x (x ∼ 70 at. %) spacer.

We experimentally demonstrate that a thin dirty superconducting (S) strip covered by low resistive normal metal (N) approaches closer to the depairing current than a single S strip, which makes its non-linear properties stronger. The obtained result comes from proximity-induced superconductivity in the N layer, its large contribution to the superconducting properties of the SN bilayer and larger sensitivity to the current than that of the host S layer. We argue that such an SN bilayer could be a promising system for different applications based on the current-dependent kinetic inductance. In addition, we also find that in the presence of the N layer the maximal vortex velocity in the resistive state considerably increases.

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Magnetic nanostructures reveal unique interface induced properties that differ from those of bulk materials, thus magnetization distributions in interface regions are of high interest. Meanwhile, direct measurement of magnetization distribution in layered nanostructures is a complicated task. Here we study magnetic field induced effects in optical second harmonic generation (SHG) in three-layer ferromagnetic / heavy metals nano films. For a certain experimental geometry, which excludes the appearance of magnetooptical effects for homogeneously magnetized structures, magnetization induced SHG intensity variation is observed. Symmetry analysis of the SHG intensity dependencies on external magnetic field shows that the nonlinear source terms proportional to the out-of-plane gradient component of magnetization govern the observed effect.

We study the perspective of thin bilayer strips made of highly resistive (in the normal state) superconductor (S) and low resistive normal metal (N) as a detector of electromagnetic radiation. A small minigap in the quasiparticle spectra, induced in the N layer due to proximity induced superconductivity from the S layer and the ability of low resistive N layer to carry a larger superconducting current than the host dirty superconductor leads to steep temperature dependence of critical current of SN strip in wide temperature ranges. It results in higher sensitivity of current-biased SN strip to the electromagnetic radiation in comparison with S strip. We present experimental results on several microns wide MoN/Cu and MoN strips, which confirm this statement in the bolometric regime. We also discuss possible advantages of single photon counting by narrow SN strips.