Observation of ferromagnetism at room temperature in polycrystalline [Zn.sub.1-x][Fe.sub.x]O solid solutions synthesized by the precursor method

• Published in: Physics of the solid state pp. 1079 - 1088
• Main Authors: Krasil'nikov, V.N, Dyachkova, T.V, Tyutyunnik, A.P, Marchenkov, V.V, Gyrdasova, O.I, Baklanova, I.V, Kuznetsov, M.V, Weber, H.W
• Format: Journal Article
• Language: English
• Published: Springer 01.06.2015
• Subjects: Ferromagnetism; Magnetization; Methods; Semiconductors; Solid solutions; Zinc oxide
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S1063783415060207

Polycrystalline [Zn.sub.1-x][Fe.sub.x]O (0 ≤ x ≤ 0.075) solid solutions with the wurtzite structure, which belong to the class of diluted magnetic semiconductors, have been synthesized by the precursor method using a mixed formate of the composition [Zn.sub.1-x][Fe.sub.x][(HCOO).sub.2] x 2[H.sub.2]O as a precursor. It has been found that the iron concentration in [Zn.sub.1-x][Fe.sub.x]O solid solutions, which exhibit ferromagnetic properties with a high degree of magnetization at room temperature, is determined by two factors: (1) the degree of substitution of iron for zinc in the structure of zinc formate Zn[(HCOO).sub.2] x 2[H.sub.2]O and, therefore, in the structure of zinc oxide ZnO and (2) the conditions of heat treatment of the precursor. It has been shown using samples with x = 0.025 and 0.05 as an example that the magnetization of [Zn.sub.1-x][Fe.sub.x]O solid solutions regularly increases with an increase in the iron concentration. Based on the results of the X-ray photoelectron spectroscopy analysis of [Zn.sub.1-x][Fe.sub.x]O powders, it has been suggested that the iron concentration increases in the surface layer of particles, and the oxidation state of iron is 3+.