Structural and physicochemical properties of nickel manganite NiMn2O4-δsynthesized by sol-gel and ultra sound assisted methods

JOURNAL OF ALLOYS AND COMPOUNDS

卷:672

Article

Alburquenque, D.^1,2  Troncoso, L.³  Denardin, J. C.³  Butera, A.⁴  Padmasree, K. D.⁵  Ortiz, J.¹  Herrera, F.¹  Marco, J. F.⁶  Gautier, J. L.¹ 

[1] USACH, Dept Chem Mat, Ave LB OHiggins 3363, Santiago 9170022, Chile

[2] USACH, Dept Met, Ave Ecuador 3469, Santiago 9170124, Chile

[3] USACH, Dept Phys, Ave Ecuador 3493, Santiago 9170124, Chile

[4] CNEA, Atom Ctr, Ito Balseiro, RA-84000 San Carlos De Bariloche, Rio Negro, Argentina

[5] Univ Saltillo, CINVESTAV, Monterrey Km 13-5, Saltillo 25900, Coahuila, Mexico

[6] CSIC, Inst Phys Chem Rocasolano, Serrano 119, Madrid 28006, Spain

关键词: Nickel manganite;    Spinel oxides;    Magnetic properties;    X-ray diffraction;    XPS;   

DOI  :  10.1016/j.jallcom.2016.02.090

来源: Elsevier

【 摘 要 】

In this work we present the structural, magnetic and surface characterization of the ceramic nickel manganite oxide NiMn2O4-delta synthesized by two methods: sol-gel and ultrasound-assisted sol-gel using nitrate salts as precursors. We have characterized the non-stoichiometric samples NiMn2O4-delta using different physicochemical analyses. X-ray diffraction and Rietveld refinement of the X-ray data indicated that the samples crystallize in the Fd3m space group characteristic of cubic spinel-related oxides. The specific surface area of the oxides was 1.3 m(2)/g (SG) and 16.3 m(2)/g (UASG). SEM results showed particle agglomerates of 1.05 mu m ( SG) and 0.85 mu m ( UASG). Temperature dependence magnetization measurements were performed and a ferrimagnetic transition was identified at 103 K and 105 K depending on the preparation method ( SG and UASG, respectively). The observed Curie constant was found to vary from 7.4 to 7.7 cm(3) K mol(-1) and hysteretic magnetization vs. applied field curves at different temperatures were obtained. XPS studies of these oxides reveal the presence of Ni2+, Mn2+, Mn3+ and Mn4+ ions at the surface. A probable ionic distribution as a function of the synthesis method is proposed. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free