Gd³⁺-Doped Magnetic Nanoparticles for Biomedical Applications

Table 1

Properties of synthesized MNPs: initial loading (χ_ini) and actual content (χ_act, by XRF data) of Gd³⁺ ions in the samples, a cubic lattice parameter (a), and average crystallite size of MNPs (d_av) calculated from XRD and TEM data, and SAR values evaluated after the hyperthermia test.

Sample name	χini Gd^3+ (mol.%)	χact Gd^3+ (mol.%)	Lattice system	a^(XRD) (Å)	dav^(XRD) (nm)	dav^(TEM) (nm)	SAR (W/g)
MNP-Gd0%	0	0	Cubic^§	8.368(8)	6	6.6	15.6
MNP-Gd0.5%	1	0.5	Cubic^§	8.385(2)	10	14.9	12.5
MNP-Gd0.6%	2.7	0.6	Cubic^§	8.348(3)	15	15.5	15.9
MNP-Gd2.5%	5.6	2.5	Cubic + orth.^‡	8.366(5)	14	14.1	15.5
MNP-Gd5.1%	7	5.1	Cubic^§	8.386(1)	15	13.3	18.0
MNP-Gd4.3%	9	4.3	Cubic + orth.^†	—	—	8.5	13.1

^§Pure inverse spinel phase (Fe₃O₄ or/and γ-Fe₂O₃); ^‡orthorhombic goethite (α-FeOOH with a = 4.59(1) Å, b = 9.90(5) Å, and c = 3.00(1) Å) and spinel phase; ^†orthorhombic goethite (α-FeOOH with a = 4.590(3) Å, b = 9.935(8) Å, and c = 3.025(2) Å) and spinel phase.