Non-classical Crystallization of Bulk Crystals in Solution and of Thin Films in the Gas Phase by Chemical Vapor Deposition

Although non-classical crystallization is a relatively revolutionary concept, where a building block for crystallization is neither an atom nor an ion but a nanoparticle, it has become so much established now that numerous papers as well as several books were published and its tutorial and technical sessions were included in international conferences. The purpose of this paper is to review how non-classical crystallization was developed in solution and in the gas phase synthesis of films by chemical vapor deposition (CVD). Findings made in the study of non-classical crystallization in solution turn out to be very useful in understanding of non-classical crystallization of thin films by CVD. Similarly, findings made in the study of non-classical crystallization of thin films by CVD would be useful in understanding of non-classical crystallization of bulk crystals in solution. Therefore, it is synergistic to review non-classical crystallization both in solution and in the gas phase. For example, the presence of charge in nanoparticles is hardly mentioned in non-classical crystallization in solution whereas it is clearly revealed by the current measurement in the gas phase synthesis of thin films by CVD. The building block in non-classical crystallization is not simply a nanoparticle but a charged nanoparticle (CNP). Many evidences indicate that charged nanoparticles (CNPs) should be liquid-like or superplastic and this property changes abruptly with their charging state and size.