Sol-gel preparation of delafossite CuCr1−xMgxO2 thin films by nitrate salts

In this paper, CuCr1−xMgxO2 thin films were prepared on sapphire substrates by the sol-gel method using all nitrate salts. With Mg doping, the grain size was decreased as well as the c-axis orientation. The resistivity was first decreased with Mg, and then increased. The CuCr0.93Mg0.07O2 thin film had the lowest resistivity with ~14 Ω cm at room temperature, and the transport mechanism was thermal activation and variable range hopping mode within the range of 200 K