Crystallization and magnetic characterizations of DyIG and HoIG nanopowders fabricated using citrate sol-gel

Abstract

a b s t r a c tDy and Ho iron garnets in form of nanoparticles were synthesized by citrate sol-gel method. Phase formation, lattice constant and average crystallite sizes of the samples were determined via XRD measurements. Morphology and particle size distribution were studied by TEM and chemical composition was checked by EDX. Magnetic measurements in temperature range 5e600 K and in the maximum applied field of 50 kOe were carried out by using SQUID and VSM. Their magnetic parameters, including Curie temperature, magnetization compensation temperature, spontaneous magnetization, high-field susceptibility, magnetic coercivity were discussed in the framework of three interacting magnetic sublattices, magnetocrystalline anisotropy, core-shell model and compared to those of the bulk materials. Based on these analyses further evaluation on the crystallinity and homogeneity of the samples has been made.

Reactive Sintering of Dysprosium-Iron Garnet via a Perovskite-Hematite Solid State Reaction and Physical Properties of the Material

“…The Curie temperature is 531 K and 550 K in the two measurement modes, which is close to literature reports, citing the values of 550 K [ 40 ] and 570 K [ 41 ].…”

“…T o is equal to 409 K in the heating mode and 396 K in the cooling mode. A similar value close to 400 K was estimated by Nguyet et al [ 40 ], but theoretical calculations of P. J. von Ranke [ 41 ] yield a slightly different value (352 K).…”

“…Table 3 shows our me3asured T comp values in the heating (220 K) and cooling mode (225 K). Several articles reported the values of T comp for DyIG garnet; T comp was found to be equal 215 K [ 40 ], 217 K [ 41 ], 218 K [ 9 ], 218.5 K [ 5 , 42 ], 223 K [ 43 ], 261 K [ 26 ]. As can be seen from this comparison, the T comp values of our sample are aligned with the majority of reported values.…”

Rare-Earth Doped Gd3−xRExFe5O12 (RE = Y, Nd, Sm, and Dy) Garnet: Structural, Magnetic, Magnetocaloric, and DFT Study

“…The RCP value depends on the −∆S M and magnetocaloric materials' operating temperature range. The RCP is calculated as follows, RCP = |∆S max M | × δT FW HM (18) where δT FWHM is the full-width-half-maxima obtained from the −∆S M vs. T plots of Figures 24-27.…”

“…The intrinsic magnetic properties of the garnet are affected by the partial substitution for Gd 3+ or Fe 3+ sites or both. Nguyet et al studied the crystallization and magnetic characterization of (Dy, Ho) 3 Fe 5 O 12 nanopowders prepared using a sol-gel technique [18]. They reported a sizeable magnetic susceptibility and coercivity compared to the corresponding values for bulk samples, a trend attributed to the disordered nature of the surface spin of single-domain particles.…”