Influence of Ti^(4+) doping on hyperfine field parameters of Mg_(0.95)Mn_(0.05)Fe_(2-2x)Ti_(2x)O_4(0≤x≤0.7)

The mixed spinel ferrite system Mg0.95Mn0.05Fe2-2xTi2xO4(0≤x≤0.7) was synthesized by the conventional solid-state reaction technique.The effect of Ti4+ doping was studied by using the Mssbauer spectroscopy measurements at room temperature.From the analysis of the Mssbauer spectra,it is observed that s-electron density,electric field gradient(EFG),quadrupole coupling constant(QCC) and the net hyperfine magnetic fields acting on the M-ssbauer nuclei-FeA3+ and FeB3+ change with the increase of Ti4+ doping in Mg0.95Mn0.05Fe2O4.The hyperfine magnetic field decreases with the increase of Ti4+ doping.

Low temperature Raman study of PrCoO_3 thin films on LaAlO_3(100) substrates grown by pulsed laser deposition

Thin films of PrCoO3 were deposited on LaAlO3 substrates by pulsed laser deposition technique.X-ray diffraction result indicates that films are single phase and c-axis textured.To investigate the spin state transition,Raman spectroscopy measurements were performed at different temperatures.The position of the Raman modes is found to increase while full width at half maximum(FWHM) of these modes is found to decrease with the decrease of temperature across spin state transition temperature(220 K) of PrCoO3.

Impedance spectroscopy study on Mn_(1+x)Fe_(2-2x)Ti_xO_4(0≤x≤0.5) ferrites

The complex impedance spectroscopy and surface morphology of Mn1+xFe2-2xTixO4(0≤x≤0.5) system,prepared using a conventional solid state reaction technique,were investigated.The impedance spectroscopy measurements were carried out at room temperature in the frequency range of 42-5 MHz.The electrical processes in the samples were modeled in the form of an equivalent circuit made up of a combination of two parallel RC circuits attributed to grain and grain boundaries.The DC conductivity obtained by extrapolation of AC data using impedance spectroscopy and four-probe method increases at 10% doping of Ti ions.The energy-dispersive X-ray(EDX) pattern confirmed the homogeneous mixing of the Mn,Fe,Ti and O atoms in pure and doped ferrite samples.

Mssbauer spectra of MnFe_(2-2x)Al_(2x)O_4(0≤x≤0.4) ferrites

The effect of non-magnetic Al3+ ion doping on the magnetic properties of MnFe2-2xAl2xO4(0≤x≤0.4) spinel ferrites was studied using Mssbauer spectroscopy measurements at room temperature.From the Mssbauer study,it is observed that the resolved hyperfine sextets are due to the distribution of Fe ions on the two sublattices of the spinel ferrites.The value of the isomer shift obtained from the fitting of the Mssbauer spectra indicates that Fe ions are in +3 state.A paramagnetic doublet is observed at degree of inversion x=0.4,superimposed on the hyperfine sextets,indicating that the super-exchange interaction A-B decreases due to the dilution of sublattice by Al3+ ions.The hyperfine magnetic field decreases at both interstitial sites of tetrahedral(A) and octahedral(B) with the increase in Al concentration.