Magnetic behavior of Mn, Al doped ZnO films obtained by PLD

FURLANI, M.G.; ZANDALIZINI, C.I.; MORENO, A.J.; OLIVA, M.I.; PUNTE, G.

Buenos Aires

Workshop; X Latin American Workshop on Magnetism, Magnetic Materials and their Applications; 2013

Different thin films of diluted magnetic semiconductors, nanostructured zinc oxide-based materials were grown by PLD and deposited on a SiN substrate (Si 100/SiO2/nitrile). The processed samples from ceramic targets of different compositions, Zn1-x-yAlx MnyO contain a same concentration of aluminium, 3% in weight, because it optimizes the value of resistivity of semiconductor [1] and different concentrations of manganese. The samples were characterized by x-ray diffraction. The chemical identification of the films constituents and their stoichiometry was obtained by ESCA electron spectroscopy and Auger spectroscopy, while the magnetic properties were explored through a MPMS-SQUID magnetometer. The XRD results enabled to determine the presence in all materials of zinc oxide with wurtzite crystal structure. In addition several manganese oxides were identified in powders samples, while the presence of zinc oxide (wurtzite) only was detected in thin films, with preferential growth in plain (002) perpendicular to the substrate. Determinations that were conducted show that the stoichiometry of the surface maintains the stoichiometry of the target which comes from, and that the material presented preferential orientation in the 002 plane. All films showed ferromagnetic behavior, even the deposited without magnetic dopant but the value of the saturation magnetization varies with the dopant concentration. El dopaje con Al tiene un efecto directo en la concentración de portadores libres, es decir que el incremento en la magnetización podría ser atribuido a la variación de portadores libres, y por consiguiente, ser unas evidencia directa de interacciones RKKY. Doping with Al has a direct effect on the concentration of free carriers, thus magnetization increase can be attributed to free carriers variation of and therefore could be one direct proof of RKKY interactions. [1] Propiedades ópticas, eléctricas y estructurales de láminas de ZnO:Al. M.G. Furlani y R.H. Buitrago. Anales AFA. Vol.13, Rosario, 2001. (En prensa).