Zinc–Cobalt Oxide Thin Films: High Curie Temperature Studied by Electron Magnetic Resonance

Abstract

The material with a high Curie temperature of cobalt-doped zinc oxide embedded with silver-nanoparticle thin films was studied by electron magnetic resonance. The nanoparticles were synthesized by the homogeneous nucleation technique. Thin films were produced with the pulsed laser deposition method. The main aim of this work was to investigate the effect of Ag nanoparticles on the magnetic properties of the films. Simultaneously, the coexisting Ag0 and Ag2+ centers in zinc oxide structures are shown. A discussion of the signal seen in the low field was conducted. To analyze the temperature dependence of the line parameters, the theory described by Becker was used. The implementation of silver nanoparticles causes a significant shift of the line, and the ferromagnetic properties occur in a wide temperature range with an estimated Curie temperature above 500 K.

Electron Magnetic Resonance Study of the Most Sensitive Metal Paint Components for Degradation

“…Spin, an intrinsic property of a particle, is the angular momentum of a nucleus or electron. EMR can detect any species with paramagnetic electrons, including organic and inorganic radicals (for example, a superoxide radical in wine [5], or phosphate transport in erythrocytes [6]), transition metal complexes [7], metalloproteins [8], biradicals [9], and more (for example, a mullite and powders used in aerospace industry [10], multi-walled carbon nanotubes and nanohorns [11], and zinc oxide thin films of dilute magnetic semiconductors [12]). EMR were also used by art restorers, historians, and restorers to study paintings.…”