Microwave-hydrothermal synthesis of Y3Fe3.35Al1.65O12 nanoparticles for magneto-hyperthermia application

Abstract

Crystalline aluminum substituted yttrium iron garnet nanoparticles Y 3 Fe 3.35 Al 1.65 O 12 (YIG) was synthesized by hydrothermal microwave synthesis at 140 °C with soaking times ranging from 15 to 60 min. X-ray diffraction confirmed the single-phase YIG nanoparticles excluding the presence of any other phases in the reaction products. The Raman spectra revealed that the largest soaking time provides greater energy crystallization causing changes of lattice vibration and a certain degree of disorder in the crystal lattice. Field emission gun-scanning electron microscopy and high resolution transmission electronic microscopic revealed a homogeneous size distribution of nanometric YIG powders with agglomerated particles. Magnetic measurements were achieved by using a vibrating-sample magnetometer unit. YIG nanoparticles have great potential in magneto-hyperthermia application once in vivo applications magnetic induction heating ferromagnetic compounds generate heat in AC magnetic fields.

Application of Ion‐Doped Y3Fe5O12 Nanoparticles for Self‐Controlled Magnetic Hyperthermia

“…The numerical calculations are in good qualitative agreement with the experimental data in other studies. [ 41,42 ] The inset in Figure 7a is again evidence that at room temperatures the surface layer is practically “magnetically dead.”…”

“…For YIGs, this is an experimental fact. [22,41] As shown in Figure 6b and 7b, the increase in the degree of doping with nonmagnetic ions of Y 3 ½Fe 2Ày M y a ðFe 3Àz M z Þ d O 12 leads to a decrease in coercivity in MNP independent of the type of doping ion. The reason for this is that the doping ions are nonmagnetic and their single-ion anisotropy is significantly smaller than that of iron magnetic ions.…”

“…YGaG YScG calculations are in good qualitative agreement with the experimental data in other studies. [41,42] The inset in Figure 7a is again evidence that at room temperatures the surface layer is practically "magnetically dead." For particles with a diameter appropriate for in vivo and in vitro therapy and with a bioacceptable temperature of the phase transition, the following values for coercivity have been obtained from numerical calculations (Table 2).…”

“…It must be noted that our numerical calculations show that below 17–19 nm, mixed‐YIG magnetic NPs pass into a superparamagnetic state and the heating process stops, which is in agreement with experimental results. [ 41 ]…”

“…Thus we can determine more candidates of ion-doped YIG MNPs for medical applications: For YAlG: d (x ¼ 1.67) ¼ 26.0 nm; d (x ¼ 1.71) ¼ 28.0 nm; It must be noted that our numerical calculations show that below 17-19 nm, mixed-YIG magnetic NPs pass into a superparamagnetic state and the heating process stops, which is in agreement with experimental results. [41] Next we calculate the saturation magnetization M S as a function of NP size (Figure 4a and 5a) as well as a function of doping concentration x (Figure 4b and 5b) for YIG. As the MNP size decreases for different x, M S decreases.…”