Structural and magneto-transport properties of cr-doped in 2O3 diluted magnetic semiconductors

N. B. Ukah, MSU Graduate Student
Ram K. Gupta, Missouri State University
Kartik C. Ghosh, Missouri State University
Pawan K. Kahol, Missouri State University
Ryan E. Giedd, Missouri State University


We report the experimental study of the structural and magnetotransport properties of chromium-doped indium oxide (In O :Cr) thin films using x-ray diffractometer, and by measuring the resistivity and Hall effect as a function of temperature in various magnetic fields. The In O :Cr diluted magnetic semiconductor thin films were grown under different partial oxygen pressures (Po2) on sapphire substrates using pulsed laser deposition (PLD) technique. Observed expansions in lattice parameter and crystal size in these films with increase in oxygen growth pressure are traceable to the reduction in oxygen vacancies. A redshift of the absorption edges of the samples with increase in oxygen growth pressure is attributed to the significant improvement in crystallinity. The exchange interaction between the electron spins in the conduction band and the spins of the Cr 3d electrons was evident in the anomalous Hall effect (AHE), which persisted up to 300 K. An analysis of the dc electrical transport in the films was carried out using hopping conduction and ionized impurity scattering models. © 2009 Materials Research Society. 2 3 2 3