Magnetic, electrical properties, and structure of Cr-AlN and Mn-AlN thin films grown on Si substrates

We have studied magnetic, electrical properties, and structure of Cr-AlN and Mn-AlN thin films grown on the Si substrates. Each magnetic state in Al_0.93Cr_0.07N and Al_0.91Mn_0.09N thin films changes from a paramagnetic state to a superparamagnetic state as temperature decreases. Room temperature (RT) ferromagnetism cannot be observed in each thin film. Each electrical property in Al_0.93Cr_0.07N and Al_0.91Mn_0.09N thin films becomes semiconducting, since the electrical resistivities of these thin films are higher than 10⁷μΩ·cm at RT. At 77 K, tunneling phenomena for the Al_0.93Cr_0.07N thin film and rectification for the Al_0.91Mn_0.09N thin film can be observed. Furthermore, the crystal structure in each thin film is also a polycrystalline structure with the preferential orientation of hcp (0001).