Directional Solidification

Non-Hall-Petch hardness dependence in ultrafine fibrous MgAl2O4-MgO eutectic ceramics fabricated by the laser-heated floating zone (LFZ) method

“…2). This fact is in agreement with the general behaviour of binary eutectics where a cross-over from fibrous to lamellar patterns is predicted at volume fractions of the minority phase above approximately 0.287 [14]. By EDS analysis, the bright matrix was detected to be spinel and the small and dark embedded phases were MgO.…”

Directional solidification of the eutectic LiF–LiYF4 using Bridgman and micro-pulling down techniques: Microstructural study and some properties

“…As this easily controllable microstructure influences the material properties, the research in directionally solidified ceramic eutectics has seen a revival in the last two decades, mainly prompted by the excellent mechanical properties of Al 2 O 3 based eutectics 2 . Concomitantly, the available procedures to prepare those materials have been recently revised 3 and new ones further developed 4 . Functional properties of these materials have also been studied 5 , for example luminescence 6,7 , up-conversion 8 , optical wave guiding 9 , red-ox behaviour 10 , ionic conductivity 11,12 , thermoemissive properties 13 , or very recently also as metamaterials and subwavelength guiding structures for the THz range 14,15,16 .…”

New polaritonic materials in the THz range made of directionally solidified halide eutectics

“…The use of this kind of composite to manufacture metamaterials has been proposed previously [9,10]. The microstructure of DSEs may consist of rods of one phase embedded into the matrix of the other phase or of alternate lamellae with a dominant alignment direction (the pulling direction or the growth direction) [11]. DSEs mimic in bulk form anisotropic phase orderings that are otherwise achieved by costly top-down or nano-fabrication approaches [12].…”

“…For the chosen materials it can be seen that  T ranges between 142 cm -1 (4.26 THz) for KCl to 306 cm -1 (9.17 THz) for LiF or 401 cm -1 (12.0 THz) for MgO; while  L ranges from 214 cm -1 (6.41 THz) for KCl to 659 cm -1 (19.8 THz) for LiF and 718 cm -1 (21.5 THz) for MgO [19]. The materials used in this study have been prepared by solidification from the melt of eutectic mixtures [11]. Directional solidification of eutectic composites consisting of phases with low melting entropy produces a solid with a microstructure of separated phases, lamellae, fibres or more complex morphologies, well aligned along the solidification direction.…”