Investigation of the Properties of CrAs(001) Half Metal Compound on the Cr and As Surface Termination

The structural and electronic properties of CrAs bulk in zinc-blende and NiAs phase have been investigated in the framework of the density functional theory by using generalized gradient approximation. The results showed that NiAs phase is stable while zinc-blende is not. The structural properties of CrAs thin film for As and Cr termination were studied too. The results showed that the As termination is more stable than Cr termination. It was found that the Cr termination has larger half-metallic energy gap than As termination. The charge density at surface layer increases as a result of the electrostatic potential which increases at the surface which is also due to loss of the surface bonds for surface atoms.