One of the most promising families of soft magnetic materials with a number of advantages, such as excellent magnetic softness, fast and inexpensive manufacturing process, dimensionality suitable for various sensor applications, and good mechanical properties, is a family of amorphous and nanocrystalline materials obtained using rapid quenching from the melt.

Such advanced functional magnetic properties have been reported in amorphous materials with either planar (ribbons) or cylindrical (wires) geometry. However, each family of amorphous materials presents specific features making them suitable for rather different applications. Thus, planar (ribbon-shaped) materials with low magnetic losses and high saturation magnetization values are good for applications in transformers. On the other hand, amorphous wires can present quite peculiar magnetic properties, such as spontaneous magnetic bistability associated with single and large Barkhausen jump or giant magnetoimpedance, GMI, effect. Although it is worth mentioning that in fact, large Barkhausen and GMI effect can be observed either in crystalline wires] as well as in properly heat treated amorphous ribbons. However, high GMI effect and extremely fast single domain wall, DW, propagation can be realized in amorphous magnetic wires in a most simple way (i.e., even without additional post-processing). Therefore, studies of amorphous and nanocrystalline materials is one of the main research topics of our group.

Magnetic wires can also present spontaneous magnetic bistability originated by a single and large Barkhausen jump between two remanent states with opposite magnetization. In such magnetically bistable wires the magnetization switching runs by fast domain wall (DW) propagation. Such DW propagation starts from the microwire ends, where the closure domains exist because of the demagnetizing field effect. In most of publications on studies of DW propagation in cylindrical amorphous micrometric and submicrometric wires the DW velocities well above 1 km/s have been reported. Such high DW velocities have been observed even in as-prepared microwires. However, such elevated DW velocity values can be further considerably improved (up to 3-4 km/s) either by appropriate annealing, or by transverse magnetic field or transverse magnetic anisotropy induced by specially designed thermal treatment.

Accordingly, studies of the mechanism of extremely fast domain wall propagation, the routes for control and further DW velocity improvement are the main research topics of our group.

Giant magnetoimpdedance (GMI) effect consists of a large change in the electrical impedance under the action of an applied magnetic field. The  principal interest the GMI effect is related to extremely high sensitivity of the impedance of magnetically soft conductor to applied magnetic field. Giant impedance sensitivity to external stimuli, like magnetic field or stress exerted by soft magnetic materials stimulated the development and implementation of various technological applications (magnetometers, magnetic field and magnetoelastic sensors) utilizing GMI materials. Good magnetic softness is directly related to the GMI effect. In most proposed applications are used amorphous wires. Accordingly, studies of the GMI effect in a wide frequency band and its correlation of magnetic ansotropy  is one of the main research topics of our group.

Rapidly solidified materials, prepared from immiscible elements (like Co-Cu, Co-Ag, …) can present granular structure. The structure of granular materials consists of nano-sized grains distributed inside a non-magnetic matrix. The pricipal interest in granular materials is related to Giant Magneto Resistance, GMR, effect  originated by spin-dependent scattering of conduction electrons within the magnetic granules as well as at the interfaces between magnetic and non-magnetic regions.

Consequently, studies of the GMR effect, temperature and magnetic field dependence of electrical resistivity in rapidly quenched materials with granulkar structire and  its correlation of magnetic properties  is one of the main research topics of our group.

In the spintronic devices that rely on magnetic textures, the objective is to have ultrafast and deterministic magnetization dynamics. The focus of our research is antiferromagnetic spintronics aiming at the development of novel concepts for information technologies. By utilizing antiferromagnets, the project aims to outline an unprecedented path for addressing the needs for ultra-fast, low power, high density, and magnetic-field insensitive devices. The antiferromagnetic dynamics can be efficiently manipulated by spin and charge currents. Spin-orbit (SO) coupling effects allow to control spins in antiferromagnets by highly efficient electrical means. It is possible to excite the dynamics by SO fields in metallic antiferromagnets with structurally broken inversion symmetry, such as CuMnAs and Mn2Au.

Antiferromagnetic spintronics offers the prospect of non-volatility and radiation hardness combined with the unique features of antiferromagnets, including: (i) robustness against external magnetic field of order ~10 T; (ii) magnetic invisibility of the encoded information; (iii) nanoscale packing density; (iv) ultrafast exchange-field enhanced spin-manipulation within THz range, compared to the typical GHz frequencies in ferromagnets; (v) a broad range of materials with robust antiferromagnetic order well above room temperature that can open a route to novel multi-functional magnetic materials for information storage and processing devices.

The term “FRC” (Fiber Reinforced Composites) usually indicates a thermosetting matrix containing fibers allowing reinforcement.

One of the most attractive features provided by modern FRC materials lies in their ability to real time non-destructive monitoring of local stresses and temperature. Recently developed composites containing piezoelectric fibers with a range of diameters from 10 to 100 μm present significant advantages over conventional piezoelectric actuators and hence have become promising technology for non-destructive monitoring. However, their operation requires electrical field supply plates occupying a significant area.

This problem can be addresses using a novel sensing technique for non-destructive monitoring utilizing ferromagnetic microwire inclusions presenting the high frequency impedance quite sensitive to tensile stress and magnetic field. One of the advantages of this technology is that proposed free space microwave spectroscopy allows remote monitoring of external stimuli, like stress or temperature.

Typical diameters of microwires (1 - 50 μm) as well as excellent mechanical and corrosive properties make this technique suitable for remote stresses and temperature monitoring in FRCs.

Consequently, ferromagnetic microwires presenting stress-sensitive magnetic properties can also be suitable for stresses monitoring in a FRC material containing such microwires by a non-contact method.

While traditional realizations of nanodevices use 2D planar structures, the future implementation of the nanoscale devices requires more energy efficient and precise multifunctional capabilities, which call for use of 3D magnetic nanostructures. Their improved capacities come from enormous increase of the active surface for storage, 3D sensing and functionalization leading to different 3D magnetic configurations, where magnetization is non-trivially dependent on three spatial coordinates. Cylindrical magnetic nanowires made of 3d metals serve as a clear and promising example. Magnetic nanowires offer multifunctional responses to electric and magnetic fields, electric current, etc., and thus can be used for the interconversion between different functionalities.

            3D domain walls (DW) and spin waves play the role of “information carriers”. While domain walls are well explored in planar nanostructures (magnetic stripes), 3D DW in cylindrical nanowires have a strong influence of the geometry and their dynamics are largely unexplored. The nanowire curved geometry leads to novel and non-trivial phenomena: i) an effective Dzyaloshinskii-Moriya interaction, thus magnetic nanowires can hold 3D skyrmions with no need of special materials, ii) Bloch-point domain walls do not suffer from the Walker breakdown, a phenomenon limiting DW speed in magnetic stripes, iii) the spin wave dispersion relation is non-reciprocal.

• Amorphous magnetic materials can present excellent soft magnetic properties together with good mechanical properties. In most cases, good magnetic softness can be obtained in as-prepared amorphous materials without sophisticated post-processing usually required for crystalline magnetic materials. In most crystalline magnetic materials, magnetic softness is essentially limited by defects, like grain boundaries, dislocations, texture, etc. Additionally, the fabrication technique, involving rapid melt quenching, is a rather fast and inexpensive fabrication method. Generally, amorphous materials can be prepared in planar (ribbons) or cylindrical (wires) forms.
• Amorphous ribbons are proposed for several applications, like transformers, magnetic shields, acoustic delay lines, tensile stress transducers and transverse filters, Inductive components for switched mode power supplies, magnetic heads for data storage applications. Amorphous magnetic wires are for several magnetic sensor applications, like magnetic field sensors, magnetoelastic sensors, magnetic memory and logics.
• The devitrification of amorphous nucleus reached by post annealing process is a useful tool allowing considerable modification of the magnetic properties and even magnetic softening in some Fe-rich microwires keeping high enough saturation magnetization. Therefore, such soft magnetic use suitable for energy efficiency applications
• One of the topics of research of our group is related to optimization of soft magnetic properties of amorphous and nanocrystalline materials

• Studies of Heusler alloys have attracted great attention owing to versatile properties (i.e. shape-memory effect, large magnetic-field-induced strain, half metallic behaviour, giant magnetocaloric effect, exchange bias …) suitable for various applications. In particularly most of proposed applications are related to magnetic cooling, actuators or energy harvesting. Up to now, a large number of Heusler alloys in bulk have been synthesized, their structure and physical properties have been intensively studied.
• The most common method for the Heusler alloys preparation is arc-melting followed by thermal treatment.  Such method allows `preparation of bulk Heusler alloys.
• Aforementioned properties of Heusler alloys can be considerably improved by miniaturization. Thus, for the magnetic cooling applications the heat exchange rate can be considerably improved if the surface-to-volume ratio can be increased by use of low dimensional Heusler alloys. Consequently novel fabrication technique allowing preparation of Heusler alloys in the form of thin wires or thin films is quite desirable. Therefore few attempts have been recently taken to prepare either thin Heusler-type wires or thin films.
• We showed glass-coated microwires technology involving rapid melt quenching can be useful for the preparation of Heusler-type magnetic microwires. Obtained microwires can present either soft or semi-hard magnetic microwires displaying Giant Magnetoresistance (GMR) effect, magnetocaloric or exchange bias effects.
• Accordingly, studies of Heusler-type microwires is one of the research topics of our group.

• Sensors provide the ability to detect and track events or changes in the environment using electronic devices, such as a computer processor, and therefore play a critical role in most modern industries (i.e., microelectronics, automotive, aerospace and aviation, security and electronic surveillance, home entertainment, computer science, medicine, construction, electrical engineering, etc.).
• Magnetic sensors have assisted in monitoring, analysis and control of various processes and functions for many decades.
• Depending on the type of events or environmental changes, different types of magnetic sensors can be used.  As a rule, the use of magnetic sensors is limited by their cost, environmental conditions and relatively weak magnetic signals. Accordingly, the main trends in the magnetic sensors are the development of cost effective, fast, precise, sensitive and effective sensing technologies and methods.
• To a great extend the sensors performance is determined by the properties of the material from which given type of magnetic sensor is made. Magnetic sensors utilizing amorphous materials are generally cost-effective, low dimensional and present excellent sensitivities.
• In our group we have developed several magnetic sensors prototypes suitable for various applications.