An experimental and theoretical study of the optical, electronic, and magnetic properties of novel inverted alpha-Cr2O3@alpha-Mn0.35Cr1.65O2.94 core shell nanoparticles

作者：Hossain Mohammad D; Mayanovic Robert A^*; Sakidja Ridwan; Benamara Mourad

来源：Journal of Materials Research, 2017, 32(2): 269-278.

DOI：10.1557/jmr.2016.504

Magnetic core-shell nanoparticles (CSNs) have potential applications in spintronic devices, drug delivery systems, and magnetic random access memory. By use of our hydrothermal nano-phase epitaxy method, we have accomplished synthesis of novel, well-ordered alpha-Cr2O3@a-Mn0.35Cr1.65O2.94 inverted CSNs. XRD and TEM analyses show a core-shell structure with corundum phase throughout the core and shell with a minimal amount of interface defects. TEM-EDX and XPS data show Mn having the 12 oxidation state in the shell of the CSNs. Magnetization measurements at 5 K show a weak coercivity (H-C) value of 8 Oe and an exchange bias field (H-E) of 293 Oe. Ab initio calculations show that Mn incorporation in alpha-Cr2O3 results in narrowing of the energy band gap, substantiated by UV-Vis measurements, and half metallic behavior in case of Mn(III) substitution. Our calculations substantiate that Mn substitution in alpha-Cr2O3 results in a combination of antiferromagnetic and weak ferrimagnetic character of our CSNs.

• 出版日期2017-1