Papers by Keyword: Mössbauer Spectra

Abstract: Six compositions: x = 0.0 to 0.5 of the spinel system Mn1.5(1-x)Ti0.5(1-x)Fe(1+ 1.5x) Li(0.5)x O4 are synthesized by ceramic method. The structural and magnetic properties are studied by means of X-ray diffraction, AC susceptibility, Magnetization and Mossbauer spectroscopy. The study reveals the significance of FeA-O-FeB magnetic linkages in evolution of long range magnetic ordering through rise in Curie temperature and growth of magnetic hyperfine field with increase in x.

Abstract: The results of X-ray diffraction, complex in-field (up to 9 T) and temperature (5300 К) Mössbauer and magnetometric studies of the ordered Fe₆₅Al_35-хM_х (M=Ga, B; x=0,5,10) and Fe_65-хV_xAl₃₅ (x=5,10) alloys are presented. Analysis of the magnetometry studies shows that the systems Fe₆₅Al₃₅ и Fe₆₅Al_35-хGa_х (x=5, 10) are characterized by two different magnetic states with essentially distinguishing hysteresis loops and AC susceptibility values. The temperature and external magnetic field values inducing the transition from one magnetic state to another are higher in the Ga-doped alloys than in the reference Fe₆₅Al₃₅ alloy. The boron addition transforms the magnetic state of the initial alloy Fe₆₅Al₃₅ into a ferromagnetic one exhibiting high magnetic characteristics. Substitution of V for Fe in the ternary alloys Fe_65-хV_xAl₃₅ results in reduction of magnetic characteristics and collapsing of ⁵⁷Fe hyperfine magnetic filed.

Abstract: In this report the results on the investigation of magnetic states of Fe and Co ions in superlattice [Mo(12Å)Co(21Å)Fe(14Å)]*100 are presented. The magnetic superlattices were obtained by means of cathode sputtering in discharge with oscillating electrons. The results of X-ray diffraction show that magnetic superlattices (MSL) have amorphous state. The magnetic states of Fe and Co ions were investigated using Mössbauer spectroscopy (MS) and electron spin resonance (ESR) for the as-deposited MSL and after annealing at 450°C. The results of our studies of Fe and Co ions states indicate that they correspond to high-spin states in clusters Fen, Com, FenCom, FenMom with small number of atoms n, m in clusters.