勝野 喜以子

Relaxation of a well polished, though atomically rough, vicinal surface of SrTiO_3 during annealing was observed by STM. The step patterns are compared with MC simulation of a lattice model.

We study the relation between growth conditions and step spacing of a crystal surface by using the Monte Carlo simulation. In our model, the initial substrate of (001) face includes only one screw dislocations. We measure the step interval under various growth conditions.

The Crystal Growth mechanism in the system more than two elements is not yet understood though is the importance. It is a cause that there are a lot of parameters of the environmental condition. We have aimed to do the Monte Carlo simulation of two element ideal solid solution to a lot of these parameters, and to give hints for theory establishment and for experimental conditions.

We examined the bound energy dependency of the effective distribution coefficient in the ideal solid solution. As a result, we clarified that the relaxation in the terrace greatly influenced the effective distribution coefficient.

Dependency of partial pressure to the relaxation process of the effective distribution coefficient at the terrace is discussed based on a computer simulation.

Monte Carlo simulation of a binary ideal solid solution crystal was done by the three models "Kink model, Step model and Surface model", and the difference between models was clarified to the relation between the growth rate and the distribution coefficient.

Two dimensional nucleation processes of alloy crystal are studied by Monte Carlo simulation. We obtained the nucleus size and the waiting time of the nucleation for the steady state nucleation growth conditions.

The cluster distribution in alloy crystal under separated conditions are investigated by Monte Carlo simulation. We show the relation between the cluster size and the distribution with the growth rate.

The stable cluster size and territory for Volmer-Weber growth mechanism are investigated by Monte Carlo simulation. It is shown that the chemical potential dependence for the cluster size shows a different tendency by the surface diffusion treatments.

We carry out the simulation of two component A-B crystals to obtain the critical nucleus size, and show that the nucleus size depends on the surface diffusion of ad atoms on substrate and depends on partial pressure ratio of vapor atoms. We treat two components system for only the case of stoichiometric A-B crystal.

We carried out Monte Carlo simulation to investigate the two dimensional nucleation processes for two components system taking account of surface diffusion on ad-atoms, and obtained the surface diffusion dependence for critical nucleus size. We found that two-dimensional kinetic critical nucleus size is strongly depended on surface diffusion of ad-atoms.

We programmed Monte Carlo simulation to analyze epitaxial growth and examined about the Ostwald ripening of the cluster which the Volmer-Weber mechanism grew.

We found the two dimensional critical nucleus size of the stoichiometric A-B crystal using Monte Carlo simulation and report on the partial pressure dependence with critical nucleus size.