Influence of Fe3+ by La3+ cations substitution on the crystallography and magnetic properties of yttrium iron garnet compound

The role of local structure and preferential site occupancy on the saturation magnetization of the Y2.97Gd0.03Fe5O12 ferrite

“…Moreover, the peaks between 400 and 800 cm −1 are associated with the Fe-O stretching in tetrahedral and octahedral local structures [17,19]. The similarity between the Raman spectra of pure (YIG) [15] and the Gd 0.03 Y 2.97 Fe 5 O 12 ferrite, along with the negligible shift in peak positions, indicates that the YIG crystal structure remains practically unchanged with the Gd 3+ (3%) ions insertion. This is due to the close relationship in size and valence state between Y 3+ and Gd 3+ ions.…”

“…By inspecting equation (4) and considering the magnetic character of Gd 3+ , it can be inferred that Gd 3+ ions induce a negative contribution to the net magnetic moment in the Gd 0.03 Y 2.97 Fe 5 O 12 compound. This can explain the difference concerning the M s value reported for the Y 3 Fe 5 O 12 compound [15]. As the Fe a -Fe d distortion in the Gd 0.03 Y 2.97 Fe 5 O 12 compound is very small (only 0.17%), the a-d super-exchange interaction weakening is not the main mechanism that determines the M s of the studied ferrimagnetic compound.…”

“…Here, s = m 0. 15 . The occupation per site probability is derived from the product of these factors and another related to the content of each constituent ion and the site characteristics, which can be expressed by a binomial function distribution as follows:…”