Spinel ferrites NiFe2O4 NCs enhanced Mossbauer spectra, magnetization and Faraday rotation of diamagnetic tellurite glasses

Glass containing magnetic nanocrystals are attractive for obtaining high magnetic and magneto-optical properties. In this study, for the first time, 10 nm cubic NiFe2O4 (NFO) nanocrystals doped heavy metal oxide glasses were fabricated and the influence of NFO to glass structure, chemical bonds, Mo & BULL;ssbauer spectra, magnetization and Faraday rotation was studied. X-ray diffraction, Raman and X-ray photoelectron spectra revealed the existence of multi-valence states of Fe/Ni ions, oxygen vacancies in cubic lattice and modifications on glass structure, which in turn adjusted the polarizability, oxygen packing density, Mossbauer spectra, magnetic property and magneto-optical behaviors. Through Mossbauer study, the increase of NFO amount enhanced the hyperfine field intensity of tetrahedral Fe3+ ions at the expense of octahedral ones. NFO doped glasses exhibited ferromagnetic behavior whose M-s and H-c increased with the NFO amount due to the NCs size effect. Verdet constant and Faraday rotation angle were studied as function of wavelength, magnetic field, polarizer angle and NFO amount. 3%NFO glass exhibited significant enhancement in magnetization and Verdet constant of 91 rad/T.m at 633 nm which is 5-fold of host glass and superior than literatures. In addition, due to the nanoscale NCs, the thermal stability of obtained NFO glasses remained higher than 100 C ? which is promising for photonics devices fabrication.

Automated summary

In this study, glass doped with NiFe2O4 nanocrystals was fabricated and its influence on glass structure, magnetic property, and magneto-optical behavior was investigated. The results showed that the doping of nanocrystals can adjust the properties of glass and achieve higher magnetization and magneto-optical performance. In addition, due to the presence of nanocrystals, the fabricated NFO glass exhibited higher thermal stability, making it promising for the fabrication of photonics devices.