Magnetic properties of Cu/Mn/O powders obteined by controlled high energetic ball milling

A. E. BIANCHI; R. VIÑA; F. SIVES; L. D. JUNCIEL; G. PUNTE

Buenos Aires

Congreso; At the Frontier of Condensed Matter III; 2006

Magnetic properties of Cu/Mn/O powders obtained by controlled high energetic ball milling Bianchi, A1., E., Viña1, R., Sives, F.2, Junciel, L. D.2,3 and Punte, G. 1 LANADI e IFLP, Departamento de Física, Facultad de Ciencias Exactas, UNLP, CC 67, 1900, La Plata 2 IFLP, Departamento de Física, Facultad de Ciencias Exactas, UNLP, CC 67, 1900 La Plata. 3 Dpto. de Electrotecnia, Facultad de Ingeniería, UNLP, CC 67, 1900, La Plata The CuXMnYOZ system shows a variety of magnetic and electrical conduction properties depending on the x, y and z values. Yang et al. [Yang, S. G. et al. Appl. Phys. Lett. 83, 3746 (2003)] have found that Cu1-XMnYO (for 0.05< x <0.15) prepared by co-precipitation methods presents ferromagnetic properties below 80K, while CuMn2O4,  synthesized following the same route, exhibits a canted antiferromagnetic behavior with a Néel temperature of about 30 K. Taking into account that the preparation way and crystallite size influence the properties of the systems of the binary oxides powders, Cu/O [Bianchi.A. et al. Report do LNLS 2003, 131-132 (2004) and references therein] and Mn/O [Bianchi.A. et al. Report do LNLS 2004], we have produced, by controlled high energetic ball milling  (HEBM) (up to 48 hs) of mixtures of CuO and α-Mn2O3 in the ratio 1/3, and studied powders of Cu/O/Mn. Selected samples were annealed at 400K during different times. All the prepared samples were characterized by x-ray diffraction and their magnetic behavior was studied from AC susceptibility measurements performed in the range 14 ?300K. Ball milled samples susceptibility curve shows a broad peak centered in 32K and increase in magnetic response as function of milling time. Thermal treatments of the 36h ball milled sample induce an increase in the magnetic response and a shift in the susceptibility maximum towards higher temperatures. These results can be rationalized as due to the stabilization of the Cu1.5Mn1.5O4 phase. [1] Yang, S. G. et al. Appl. Phys. Lett. 83, 3746 (2003) [2] Bianchi.A. et al. Report do LNLS 2003, 131-132 (2004) and references therein [3] Bianchi.A. et al. Report do LNLS 2004, in press.