Magnetic properties of amorphous, p-type conducting CuCr0.95Mg0.05O2 and CuCr0.93Mg0.05Mn0.02O2

CuCr0.95Mg0.05O2 has been reported to be p-type oxide semiconductor with the highest conductivity determined by the Seebeck effect [1]. We prepared conductive, polycrystalline and amorphous CuCr0.95Mg0.05O2 and CuCr0.93Mg0.05Mn0.02O2 films on a-plane sapphire substrates by pulsed laser deposition under different O2 partial pressure and substrate temperature. Hall measurements were performed to study the majority carrier type in these films. The polycrystalline CuCr0.95Mg0.05O2 and CuCr0.93Mg0.05Mn0.02O2 films are n-type conducting up to 290 K, while in amorphous CuCr0.95Mg0.05O2 and CuCr0.93Mg0.05Mn0.02O2 films the type of majority charge carriers changes from n-type to p-type around 270 K. Interestingly, the structure has little influence on the magnetic properties of the films. The well-known antiferromagnetic to paramagnetic transition was observed in both polycrystalline and amorphous CuCr0.95Mg0.05O2 films at 25 K, while the CuCr0.93Mg0.05Mn0.02O2 films revealed no antiferromagnetic ordering below 25 K.
[1] R. Nagarajan et al. J. Appl. Phys. 89, 8022 (2001)