Laboratory of Magnetodynamics

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Laboratory Staff

Selected Publications

Research Focus

The long-term focus of the Laboratory of Magnetodynamics has been the magnetic recording media fundamentals and fabrication technology. Our researchers succeeded in this field, having developed a (Co80Ni20)1-xNx film material for high-density magnetic recording and fabricated a hard magnetic disk on its basis. We intensively investigate the dynamics of domain walls in films and single crystals. We found and studied the resonance of the internal structure of a domain wall (Bloch line). We developed a method for magneto-optical detection of induced domain-wall vibrations.

Currently, our team works at the magnetic multilayer fabrication technology.

We study

  • magnetic and magneto-transport properties of multilayers ferromagnetic metal / semiconductor (semimetal),
  • magnetic and magneto-transport properties of multi-component oxide films,
  • multiferroics and nanocomposite films ferromagnetic metal / oxide for magneto-optical applications.

We develop CoPt, CoPd, FePt, and FePd-alloy-based ultrahigh density magnetic recording media with the perpendicular magnetic anisotropy. The magnetic structure of the multilayers and single crystals is investigated by nuclear magnetic resonance methods, including the nuclear echo testing approach created by our researches.

Advanced developments

Of our special interest are multilayer magnetic films in the system transition metal / semiconductor with the exchange bias effect as promising candidates for application in devices based on the spin-dependent electron transport. Here, we obtained a number of the priority results, specifically

  • demonstrated the existence of the temperature-dependent exchange in films with a semiconductor spacer,
  • found the photo-induced variation in the interlayer exchange,
  • established the dependence of the interlayer exchange on a magnetic field and a ferromagnetic layer thickness,
  • disclosed the spin-glass-like behavior of the magnetization in weak magnetic fields,
  • studied the effect of the semimetal bismuth spacer in FeNi/Bi/FeNi films on the value and sign of the interlayer exchange and revealed giant magnetoresistance in the NiFe/Bi/NiFe structure,
  • fabricated for the first time (Tb, Dy-Fe, Co)/NiFe bilayers with the orthogonal orientation of the easy magnetization axis in the layers with the unidirectional exchange magnetic anisotropy for application in spin-valve devices.

At the Laboratory, materials for magneto-optical devices are developed and fabricated on the basis of multi-component oxide compounds and alloys rare-earth element / 3d metal. Among them are Bi1.7Y1.3Ga1.8Fe3.2O12- and CrCoFeO4-based polycrystalline films with high magnetic and magneto-optical parameters. We optimized the magneto-optical medium for magnetic photonic crystals.

We synthesized composite Co/TiO2 nanogranular films and layered structures with 5-nm-thick Co and 17-nm-thick TiO2 consisting of 2--12 layers. In the nanogranular films, we found the resonance increase in the Kerr rotation angle near the percolation threshold by a factor of 3--3.5. We demonstrated that the magneto-optical spectra of the Co/TiO2 layered structures are resonance with a significant (by a factor of ~10) increase in the Kerr rotation angle near the resonance.

Equipment

SKF-01 Universal Magneto-Optical Stand

NanoMOKE 2 Magneto-Optical Facility (Durham Magneto Optics Ltd.)

Ultrahigh Vacuum Four-Target Magnetron Sputtering System

01NI-7-006 Oratoriya-5 Continuous Operation Set

Magnetic Property Measurement System (MPMS)

High-Temperature Vibrating Sample Magnetometer

Veeco MultiMode NanoScope IIIa SPM System