Materials Development Division
- Assoc. Prof. Junpei OKADA
- Assist. Prof. Haruhiko KOIZUMI
- Assist. Prof. Jun NOZAWA
Lead New Growth Methods with Optimizing Interfacial Energies by Applying External Fields
Development of almost every functional material and device in the area of information technology has been aided by the research of the associated single crystal. This lab is concerned with the novel approach mainly for the growth from the melt by studying the relationship between the interface dynamics during growth and properties of grown crystals.
Special interests lie in the growth of new crystals via the manipulation of the interface dynamics (1) by the imposition of an interface-electric, -magnetic and -stress fields and (2) by the change of the solid-liquid energy relationship through the thermal or mechanical treatment on the solid or liquid. Combining these approaches will also shed new light on the crystal growth that has never been successful. Crystals developed this way will widen an application opportunity in the piezoelectric, magnetic, optic and other fields related to the highly-networked information society.
crystal growth, chemical potential, applying external fields
(a)Inside of ESL chamber. A spherical sample is levitated using electrostatic force.
(b)A SEM image of quenched samples from supercooled liquid Si.
To quench supercooles states of high temperature liquids, we have developed a unique liquid-quenching system including an electrostatic levitator (ESL). (a) In the ESL system, a sample was levitated between the two horizontal electrodes using electrostatic forces via a feedback loop. (b) A characteristic microstructure was observed locally in the quenched Si sample. The microstructure composed of Si grains with a diameter of several tens of nm hints that amorphous Si could be locally formed once in the quenching process and then transformed to crystal Si grains by latent heats form the surroundings