Relationships between crystal structure and magnetic properties in type-A heteroepitaxial MnAs thin films

摘要

We grew heteroepitaxial type-A MnAs thin films on GaAs(001) and Si(001) substrates and compared their crystal structures and magnetic properties. The type-A MnAs on the GaAs(001) substrate shows similar structural and magnetic properties as those in bulk form. However, the structure of the type-A MnAs on the Si(001) substrate is compressed and stretched along the MnAs[1100] and MnAs[1120] directions, respectively, and exhibits weak ferromagnetism with a T_c exceeding 400 K. These experimental observations indicate that the magnetic characteristics of MnAs are strongly correlated to the material's crystal structure.