Ferromagnetism in Co doped SnO2 film

F. GOLMAR, A.M. MUDARRA NAVARRO, C.E. RODRÍGUEZ TORRES, F.D. SACCONE, F.H. SÁNCHEZ

Buenos Aires

Simposio; International Symposium on Metastable, Amorphous and Nanostructured Materials; 2008

UBA-CONICET-CIDIDI

In recent years teh interest for the physical properties of diluted magnetic semiconductors has significantly increased due to their potential technological applications in the field of optoelectronics. Many studies report on high temperature ferromagnetism in oxide materials such as TM doped anatase (TiO2), zinc oxide and tin dioxide with TM: Co, Ni, Cr, Mn, V and Fe. SnO2 presents special properties, such as transparency and remarkable chemical and thermal stabilities. Many works reported feromagnetic properties of TM-doped single crystal SnO2 thin films. Nevertheless ferromagnetism is much more difficult to find yb polycrystalline samples. These controversial observations raise questions about the nature (intrinsic or extrinsic) of ferromagnetism in these systems. This is of particular importance since recent studies on DMS thn films suggested that ferromagnetism could have an extrinsic origin(1). In this work we present a study of the magnetic properties of Co doped SnO2 film grown on LaAlO3 single crystal substrateby pulsed laser ablation. While at room temperature the film is ferromagnetic-like with loe coercivity (almost zero) at 5 K the coercivity increases to 540 Oe. The magnetization vs temperature curves showed the superposition of paramagnetic and ferromagnetic contributions and an antiferromagnetic transition is observed at about 45 K. The origin of the magnetic hardening of the ferromagnetic component could be related to the apparition of the antiferomagnetic phase. (1) Belgahzi et al. Appl. Phys. Lett. 2006, 89, 122504