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This work reports the bulk structural and magnetic properties of Bi1-xLaxFeO3 with x= 0, 0.1 and 0.2 using XRD and magnetization studies. Magnetic hyperfine fields and quadrupole splitting at Fe sites associated with FeO6 have been discussed in a detailed manner corresponding to pristine and La doped BiFeO3 using Mössbauer spectroscopy. [ABSTRACT FROM AUTHOR]

The Pb0.8Bi0.2Fe0.6Nb0.4O3 (PFN-BFO) multiferroic solid solution was synthesized by single step solid state reaction method with low calcination (700 °C/2h) and sintering (800 °C/3h) temperatures. Single phase formation was confirmed through X Ray Diffraction (XRD) and Neutron Diffraction (ND) at room temperature (RT). The structural analysis was carried out by Rietveld refinement through the Fullprof program. Refined XRD and ND patterns confirms the monoclinic structure with Cm space group and obtained cell parameters from the ND data are a = 5.6449(8) Å, b = 5.6536(5) Å, c = 4.0017(6)Å and β = 89.930(4)°.ND data at RT exhibits G-type antiferromagnetic structure. The Mössbauer and Electron Paramagnetic Resonance (EPR) spectroscopy studies were carried out at RT. The isomer shift and the quadrupole splitting of the Mössbauer spectra confirm the Fe in +3 states. An EPR spectrum shows a single broad slight asymmetric line, is an evidence of Fe in +3 states. ND, Mössbauer and EPR studies are the clear evidence of existence of antiferromagnetic ordering near room temperature. [ABSTRACT FROM AUTHOR]

The FeAl alloy formation takes place during mechanical alloying of Fe-50%Al elemental powder. During this process, Iron nanoparticles have been embedded in aluminium matrix as a result of fracturing and cold welding. The Mössbauer spectra of as milled samples have been taken at room temperature. The Mössbauer spectrum of unmilled sample shows only the presence of an a-Fe sextet where as the milled samples at room temperature shows a hyperfine sextet corresponding to Fe rich solid solution and quadrupole doublet corresponding to Al rich solid solution. In the quadrupole component, the quadrupole splitting is decreased from 0.35mm/Sec (for 2 hours milling) to 0.27mm/Sec (for 3 hours milling) which indicates the transformation of Al rich paramagnetic AlFey solid solution into the paramagnetic BCC Fe-Al phase. The un-reacted Fe clusters are responsible for an observed magnetic moment. [ABSTRACT FROM AUTHOR]

The effects of disorder on the magnetic properties of Co2FeAl alloy are reported. X-ray diffraction exhibit A2- type disordered structure. Room temperature Mössbauer studies show the presence of two sextets with hyperfine field values of 31T and 30T along with a nonmagnetic singlet. The electronic structure of ordered and disordered Co2FeAl alloys, investigated by means of the KKR Green's-function method shows that the magnetic moment of the ordered structure is 5.08µB and is 5.10µB when disordered. However, a much higher magnetic moment of 5.74µB is observed experimentally. [ABSTRACT FROM AUTHOR]

The σ-phase of FexCr1-x, x = 0.50 - 0.56, was investigated by neutron, magnetization and high field 57Fe Mössbauer measurements to gain information about the magnetic ground state. Low ordered and high paramagnetic moments indicate strongly delocalized Fe-moments. Local hyperfine fields for the five crystallographically different lattice sites were determined, which are non linearly related to the moments, indicating that large valence contributions to the hyperfine fields are present. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]