Our laboratory, founded in 2003 as the crystal chemistry research laboratory of IMR, was based on the recognition that the development of almost every functional material and device in the area of information technology has been aided by the improvement of the associated single crystals. Our lab has been concerned with novel growth methods, mainly from a melt or a solution, focusing on the role of the local equilibrium and growth dynamics at the interface. The principle underlying our research is the use of the ‘freedom’ present at the interface. An increase in freedom allows a more variable growth process, while a decrease in freedom confines the growth conditions necessary to obtain a homogeneous crystal. Research areas associated with this principle are: (1) Growth under an applied electric field, (2) Growth of a new ferroelectric crystal that is both stoichiometric and congruent, and (3) Phase transition studies at a microscopic scale via colloidal crystallization.
Materials Development Division
Crystal Chemistry Research Laboratory
Prof.Takahiko SASAKI
- Assoc. Prof. Junpei OKADA
Lead New Growth Methods with Optimizing Interfacial Energies by Applying External Fields
True congruent-melting growth never presents the compositional change even when it confronts a sudden change of growth rate due to the perturbation at the interface. MgO concentration change was examined when the MgO-doped congruent LiNbO³ c rystal in s teady-state growth e xperienced a sudden change of growth rate from 5mm/h to 40mm/h. (a) Conventional congruent-melting growth. Mg concentration change is remarkable at the sudden change of growth rate. (b) True congruent-melting growth. There is no Mg concentration change at the sudden change of growth rate.
The reversible condensation and crystallization induced with the aid of intense plasmonic near-field in the proximity of the metal nanostructure. This crystallization method allows us not only to control crystallization precisely but also to observe unprecedented dissolution process which has never been observed in spontaneous crystallization.