Mossbauer studies of Zn-substituted BiFeO3 multiferroic

This work presents an elaborate study of the effect in the structural and magnetic of BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.05, 0.10, 0.15, 0.20, 0.25) multiferroic materials, synthesized via a sol-gel auto-combustion method. The synthesized materials are found to have structural distortion in the rhombohedral R3c structure as observed by X-ray diffraction (XRD). Other diffraction peaks were attributed to the second phase Bi[Formula: see text]FeO[Formula: see text]. The Mossbauer spectra (MS) of BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.05, 0.10, 0.15) are fitted with a sextet and a doublet, and the presence of doublet also indicates the Bi[Formula: see text]FeO[Formula: see text] phase. The results from XRD and MS both show that Zn-substituted BiFeO3 suffers adverse effects on the formation of pure BiFeO3. BiFe[Formula: see text]Zn[Formula: see text]O3 ([Formula: see text], 0.25) are fitted with only one paramagnetic doublet. The absence of sextet means that there is a magnetic destruction of samples on account of a thorough phase transition from a magnetic phase to a non-magnetic phase and/or successful ion substitution (iron ions were replaced with zinc ions).

Study of Nature of Paramagnetic Doublet in Mössbauer Spectra of Mice Liver Using External Magnetic Field

A process of the biodegradationin vivoof a magnetic ferrofluid was investigated by Mössbauer spectroscopy. After the injection of the ferrofluid in a mice body an additional doublet was observed in the Mössbauer spectra of the mice liver. Further analysis showed that the doublet consists of two components with different magnetic properties. The components related both to the formation of non-magnetic ferritin-like proteins and superparamagnetic behavior of the injected nanoparticles. These components were separated in an external magnetic field and the time evolution of each fraction was studied. The concentration of both of these fractions in the frame of multi-level relaxation model was estimated.

STRUCTURAL, ELECTRONIC STRUCTURE, TRANSPORT AND MAGNETIC STUDIES OF NdFe1-xNixO3(x = 0.4, 0.5)

The structural, transport, electronic structure and magnetic properties of NdFe 1-x Ni x O 3(x = 0.4, 0.5) samples are studied. Both the samples are in single phase with orthorhombic Pbnm structure. The transport properties show the semiconducting nature of the system and no transition is seen on the application of magnetic field. The electronic structure studies verify the chemical states of the ions in the embedded system and the symmetry of the interacting ions. The magnetic properties show the transition from ferromagnetic to paramagnetic phase and which is studied through the Mossbauer studies. The paramagnetic doublet in the x = 0.5 system clearly shows the phase transition from ferromagnetic to paramagnetic.

Mössbauer Spectroscopic Analysis of Nd2Fe14B/α-Fe Hard Magnetic Nanocomposites

Among novel magnetic intermetallics based on rare earth-transition compounds, the Nd2Fe14B/α-Fe isotropic nanocomposites have been obtained by recrystallization from an amorphous phase, prepared by melt spinning. For variable 5 wt.% Fe and 10 wt.% Fe contents we recorded transmission 57Fe Mössbauer spectra at the room temperature, hardened of the α-Fe phase by exchange interactions. The spectra have been analyzed in terms of ten Zeeman sextets and one paramagnetic doublet related to the Nd1.1Fe4B4 phase. One sextet corresponds to the α-Fe phase, whereas others are attributed to six non-equivalent Fe sites in the Nd2Fe14B structure, namely 16k1, 16k2, 8j1, 8j2, 4c, and 4e. The three remaining sextets belong to the Fe3B structure with three inequivalent Fe sites FeI(8g), FeII(8g) and FeIII(8g). All relevant parameters for both nanocomposites: the magnetic hyperfine field, the isomer shift and the quadrupole splitting are determined for each of these sites.