Laboratory of Physics of Magnetic Films

Laboratory Staff

Selected Publications

 The Laboratory of Physics of Magnetic Films is headed by Dr. 

Research Focus

  • fabrication and study of nanocrystalline and amorphous ferromagnetic films based on 3d metals;
  • synthesis of nanomaterials with controllable shape, composition, structure, and properties;
  • development of novel magnetic nanostructures and techniques for their fabrication;
  • development of methods for investigating the synthesized structures and search for the features of their properties;
  • study of the correlation between the structure and magnetic properties of the synthesized materials.

We prepare magnetic films by

  • vacuum thermal evaporation deposition,
  • chemical deposition,
  • pulsed plasma assisted magnetron sputtering.

Equipment

Vibrating Magnetometer (field range 0--14 kOe, temperature range 77--300 K, accuracy of no worse than 10-4 emu)

Microwave Spectrometer (field range 0--20 kOe, frequency of 9.2 GHz)

Similar to other nanomaterials, thin films represent a special class of solids with unique properties. Structurally, they are divided in amorphous and nanocrystalline. Characteristics of thin films are determined by the properties of nanosized grains forming the films and their interactions with one another.

3d-metal films of a new type have recently been fabricated using pulsed plasma assisted vacuum sputtering. The feature of this fabrication technique is an extremely high sputtering rate (about 1000 nm/s at a sputtering pulse length of ~0.1 ms). Our team investigates atomic, magnetic, and electron structure and properties of the films obtained by this method and film evolution during annealing.

According to the results of investigations of the structural parameters, these films consist of nanosized (< 5 nm) crystal metal clusters surrounded by carbon atoms. Annealing induces the crystallization processes in the films. The electron diffraction data show that multiple twinning of the structure upon crystallization leads to the occurrence of the superstructural reflections. The twinning can occur at merging of nanocrystal clusters with the shape of cube octahedra. Annealing leads to the transformation of the nanocrystalline state, through a sequence of metastable phases, to the stable structure of a bulk 3d metal.

In the framework of the structural model built by us with the use of the self-consistent simulation of nanoclusters, we explain the magnetic properties of the films obtained. Currently, we develop the description of the temperature dependence of electric conductivity in the scope of the model of reflection of conduction electrons at the grain boundaries.

The investigated nanocrystalline magnetic films are of special interest for application, in particular, in magnetic recording.

 

 

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