Abstract
This is a study on structure and magnetic properties of Ga1-xMnxAs fabricated by ion beam induced epitaxial recrystallization (IBIEC). In this thesis, the Ga1-xMnxAs thin film was made by Mn implantation into GaAs wafer and following ion beam irradiation.But it is notorious that Mn implanted GaAs usually has 2nd phase precipitation due to the Mn solubility of GaAs is low at high temperature annealing. Ion beam induced epitaxial recrystallization is a unique technique to regrowth damage crystal at low temperature. So we applied this technique to prepare the Ga1-xMnxAs thin film. This thesis was focus on the exclusion of the existence of 2nd phase and tried to identify the local structure of Mn implanted GaAs. In order to clarify the annealed Mn-implanted GaAs was the single phase zincblende Ga1-xMnxAs compound, a series of analyses (Channeling, TEM, XRD, SIMS XAS etc) were made to study its structure. It was proven that the structure of IBIEC treated Mn implanted GaAs form the Ga1-xMnxAs structure, i.e. Mn atoms substitute Ga atom and form zincblende type Ga1-xMnxAs.The magnetic properties were measured by Superconducting Quantum Interference Device (SQUID) magnetometry, X-ray Magnetic Circular Dichoism (XMCD) and Magnetic force Microscopy (MFM). The results confirmed that the Ga1-xMnxAs prepared by Mn implantation and following IBIEC treatment has room temperature ferromagnetism.