Scale invariance of the structure upon explosive crystallization of amorphous films

The Self-Organisation of Tetrahedrally Close-Packed Structures in Magnetic Nanocrystalline Tb-Fe and Co-Pd Films

“…Figure 1 shows the electron microscopy image of the Fe−Tb thin film where the explosive crystallisation propagates in the periodic turbulent regime that can be identified as the Teilor vortexes. Similar pictures were observed in CoPd films [4,5]. Saturation magnetization (M s ) decreases with increase of the annealing temperature (Т ann ) over the range from 300 to 500°C (see Fig.…”

“…4c. All the above mentioned forms are observed in our study [4,5,10]. The electron diffraction patterns taken from all the samples CoPd, Co-C, Fe-C, Fe 2 Tb allowed to identify the tetrahedrally closed-packed Frank-Kasper structure of a cubic Laves phase type [16].…”

“…Because of the temperature and pressure gradients, the hydrodynamic and thermal effects competition yields complex periodic, quasiperiodic, and chaotic structures. The self-organization of an atomic structure in Tb 30 Fe 70 and Co 50 Pd 50 films possessing of high values of the PMA constant (K ⊥ ~ 10 6 erg/cm 3 ), was studied by transmission electron microscopy (TEM) and electron diffraction [4,5]. The crystallisation of the films occurs in an explosive way with formation of a large variety of structures from the initial nanocrystalline state to dendritic, fractal, lens (hyperbolic and elliptic umbilica), Hele-Shaw cells, shock-wave fingers, Teilor vortex, and autowave process tracks in mezzo-scale.…”

“…The crystallisation of the films occurs in an explosive way with formation of a large variety of structures from the initial nanocrystalline state to dendritic, fractal, lens (hyperbolic and elliptic umbilica), Hele-Shaw cells, shock-wave fingers, Teilor vortex, and autowave process tracks in mezzo-scale. It was shown that after the crystallisation (Т ann ~ 260°C − 330°C) the atomic structures of Tb 30 Fe 70 and Co 50 Pd 50 films are tetrahedrally close-packed [5]. Such atomic structures are typical for Tb-Fe alloys but not for Co-Pd ones.…”

Long-range correlations in the structure of fractal films

“…2c, 2d). It is known that nanosized structure elements (e.g., nanocrystallites) in a nonequilibrium process in a dis ordered solid ensure the scale invariance of the distri bution of stress fields at microscopic and mesoscopic levels owing to mobility and adaptivity: the scale invariance of the structure is observed in thin films under extreme conditions (see, e.g., [21]). …”