Magnetic transitions in (Co, Fe)-doped ZnO nanoparticles: A Mössbauer and critical exponents study

Tupan L.F.S.; Valerio-Cuadros M.I.; Oliveira A.A.; de Brito A.S.; de Souza A.O.; Barco R.; Passamani E.C.; Ivashita F.F.; Paesano A., Jr. · Materials Chemistry and Physics (2023) · DOI: 10.1016/j.matchemphys.2023.127665

Resumen

Zn1-2zFezCozO nanoparticles were synthesized by a lyophilization process followed by thermal annealing. These samples were structurally and magnetically characterized to detail the magnetic ordering at room temperature in magnetic-doped semiconductors. X-ray diffraction results showed that the samples were monophasic for z ≤ 0.03 whereas 57Fe Mössbauer spectroscopy displayed two groups of iron ions substitutional to zinc cations in the wurtzite matrix: isolated iron and iron ions with magnetic neighbors. Magnetic characterization was supported by critical transition analyses and revealed that the samples were paramagnetic at room temperature and transited to a spin-glass-like state at low temperatures after crossing a temperature region with competing ferromagnetic and antiferromagnetic interactions. The study based on critical exponents could be applied successfully for other 3d-doped oxide nanoparticle systems.

Instituciones: Universidad Nacional Mayor de San Marcos