HEBM Cu/Mn/O powders: structuralcharacterization and properties

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

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Congreso; Reunión Nacional de Sólidos 05; 2005

HEBM Cu/Mn/O powders: structural characterization and properties   Bianchi, A., Viña, R., Sives, F., Junciel, L. and Punte, G   The CuxMnyOzsystem has shown a variety of interesting 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-xMnxO (for 0.05 < x < 0.15) presents ferromagnetic properties below 80K, while CuMn2O4 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 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, in press], we have produced and studied powders of Cu/O/Mn. Samples, obtained by controlled HEBM (up to 96 hs) of mixtures of CuO and aMn2O3, in the ratios 1/3 and 2/3, were characterized by X ray powder diffraction at room temperature. The average volume-weighted crystallite size and the weighted average strain of the phases observed were determined from the Rietveld analysis of the DRX data; their magnetic behavior was studied from AC susceptibility measurements performed in the range 14 ?300K. These results will be compared with that ones coming from nanostructures produced by HEBM the original binary oxides [Bianchi.A. et al. Report do LNLS 2003, 131-132 (2004) and references therein,  Bianchi.A. et al. Report do LNLS 2004, in press ] and from mixtures, in the appropriate proportions, of the binary oxides powders.   [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.