Disordered Metastable Metallic Systems Prepared by Rapid Quenching

 
 

Department of Metal Physics

 

 

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Research:

Metallic glasses and related systems prepared by rapid quenching from the melt exhibit, unlike conventional polycrystalline matter, specific features related to local spatial (dis)ordering of atoms and to local chemical composition resulting from freezing of the melt structure and leading to the formation of complex metastable amorphous structure. These features lead to novel properties of metastable systems controlled by micro and nanostructure and yield high-performance materials with special nonconventional combinations of properties generally absenting in stable-state materials.

Physical procedure of preparation of metallic glasses by rapid quenching consists of two steps:

melting of suitable components corresponding to the desired final chemical composition of the material, yielding homogeneous polycrystalline master alloy (in stable state)
melting of master alloy and its rapid quenching to obtain amorphous structure (in metastable state)

 

By this procedure complex amorphous and nanocrystalline structure in form of thin ribbons is obtained.

Physical Research of Complex Disordered Structures is Focused on:

amorphous, nanocrystalline and quasicrystalline systems
thermodynamics of amorphous (metastable) state
short-range ordering in rapidly quenched structures
phase transitions, stability and rates of transformation
structure and phase analysis
computer simulation of atomic and electronic structure
magnetic properties (magnetic anisotropy, mechanism of remagnetization,
magnetisation, permeability, coercivity, magnetic aftereffects)
mechanical and magnetoelastic properties, Curie temperature
melt properties and solidification process
atomic and electron transport
(viscosity, electrical conductivity, Hall effect, giant magnetoresistance)

Methods of Research:

electron microscopy (TEM, ED, HREM, SEM, EDX)
X-ray spectroscopy
positron annihilation lifetime methods
thermoanalytical methods (DSC, DTA)
high precision electrical resistivity
magnetostriction
dilatation
microprocess modelling
atomic and electronic structure simulation
magnetic and magnetoelastic characterization
densitometry
chemical analysis (ICP)
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