Fractal growth of Ga6Mn phase in thin Ga97Mn3 amorphous films

Geometric patterns formed after crystallization of GaMn amorphous films with Ga-rich compositions higher than about 80 at.% Ga were investigated by means of transmission electron microscopy. Two basically different types of the patterns were found to occur depending on the composition of the amorphous films. One, observed upon crystallization of the Ga₆Mn phase from the Ga₉₇Mn₃ amorphous, was composed of random ramified branches which are very similar to those formed by diffusion-limited aggregation (DLA) in two dimension, and showed the fractal dimension of D = 1.7. Another pattern was developed upon crystallization of the Ga₈₁Mn₁₉ amorphous, exhibiting a dense radial distribution of Ga₄Mn crystallites, which resembled the Eden cluster with a non fractal character. Materials parameters affecting the pattern formation are discussed.     

Giant magnetostriction of amorphous TbxFe1-x (0.10

J Huang  C Prados  JE Evetts  A Hernando 《Canadian Metallurgical Quarterly》1995,51(1):297-304

Crystallization behavior of amorphous Cu48Ti52: Formation of an intermediate long-period superlattice phase

Amorphous Cu₄₈Ti₅₂ crystallizes during continuous heating by a two-step process involving initial polymorphic transformation to a long period superlattice structure followed by decomposition to the equilibrium phases. From TEM lattice fringe imaging and diffraction data, an antiphase boundary (APB) model for the superlattice structure based on the equilibrium CuTi phase is proposed. The antiphase boundaries have a structure related to the minority equilibrium phase CuTi₂. During longer anneals, oriented precipitates of CuTi₂ form in the CuTi matrix with an orientation relationship rotated 90° from that of the APB structure. The reorientation minimizes strain energy between the lattices.     

Crystallization of thin amorphous TiB2 films when heated in electron diffraction column

The change in the structure of amorphous TiB₂ thin films ～40 nm thick in heating in an electron diffraction column is studied. Amorphous films are produced by magnetron sputtering a titanium diboride target prepared by powder metallurgy method in argon. It is determined that crystal borides (from lower to higher) appear with increasing heating temperature. The correlation is established between the crystallization temperature and Ti-B bonding energy.     

Effect of magnetic layer thickness on magnetic properties of Ce-Fe-B thin films

The Ce_2 Fe_(14)B thin films with a notable out-of-plane c-axis texture were prepared by DC magnetron sputtering on a Ta buffer layer. The morphological and magnetic properties were investigated. The thickness of the magnetic layer had a dramatic effect on the formation of Ce_2 Fe_(14)B phase,and excellent magnetic properties(H_(ci)≈4.25 kOe, M_r/M_s≈0.81) were observed for the Ce-Fe-B film with the thickness d_m = 200 nm. The results of the hysteresis loops for Ce-Fe-B film(d_m = 200 nm) at various measured temperatures show that a decoupling between the hard and the soft phases is observed at low temperatures, which is due to the regions with quite low anisotropy provided by the a-Fe. Moreover. it is clear that significantly various magnetization behaviors between the films with d_m = 200 and 300 nm were observed with a similar trend due to the existence of the a-Fe soft phase.