磁性石榴石薄膜的液相外延生长机理

为了对磁性石榴石薄膜液相外延过程中熔质成分作定量的评估,本文根据扩散-反应方程,建立了熔质浓度分布模型,研究了液相外延生长中熔质R_2O_3(R代表稀土元素)和Fe_2O_3的浓度在PbO/B_2O_3作为助熔剂的熔体中的变化状况,以及薄膜线性生长速率与生长温度的关系.

Liquid Phase Epitaxial Growth Mechanism of Magnetic Garnet Films

The liquid phase epitaxial (LPE) process is in fact a one-dimensional system with only diffusion and the chemical reaction. As steady crystals are continuously formed during solute reactions, the distributions of the solute concentrations will vary with time. None of the existing LPE growth models is capable of describing the variation. On the basis of the Van Erk model and the diffusion-reaction equation, a new solute concentration distribution model has been developed and used to investigate the concentration variation of both the solutes R2O3 (R representing the rare-earth element) and Fe2O3 in the melt with PbO and B2O3 as flux during the LPE process. Results show that the diffusion rates of the solute increase linearly with an increase of the degree of supercooling. As the rotating speed of the substrate increases, the solute concentrations increase everywhere, which agrees with the conclusion that the increase of the rotating speed of the substrate accelerates the chemical reaction in the LPE process.