Ferri-spin glass nature of spinel ferrites Gax Fe1−x Ni Cr O4

Mössbauer measurements in mixed spinel ferrite Ga_x Fe_1–x Ni Cr O₄ (0x0.8), carried out between 4.2 and 298°K, show the presence of entropic spins in this system. Recent Monte Carlo calculations /4/ have predicted the presence of such spins in a frustrated spin glass lattice.     

Fermion masses

In this paper, we show that 2m _e m /(m _e ² +m ² = (g _V/g _A) _e ² . From this expression, the Weinberg mixing parameter is shown to be 0·2254 or 0·2746. Assuming that the electron and muon neutrino masses are degenerate, we find thatm _v = (g _V/g _A) _e ² . (m _e m )/M _WL, where M_WL is the mass of the standard W^± boson. The neutrino mass turns out to be 6·5 eV. The -neutrino mass is found to be about 81 MeV. The masses of c, t, s and b quarks are found to be respectively 1·7 GeV, 21·2 GeV, 0·57 GeV and 2·18 GeV by assumingm _d=m _u= 0·3 GeV. All these masses agree with other estimates except the b quark which has about half of its expected value.     

Mössbauer spectroscopy study of iron corrosion underneath painting system

The effect of pigments on the development of corrosion products between the painting system and metal surface when exposed to marine environments has been discussed. The pigments studied were; Red Mud Zinc chromate, Zinc chromate, Red oxide Zinc Phosphate, Manganese Phosphate Barium chromate and Basic Lead Silico Chromate. Mossbauer Spectroscopy revealed that the upper rust layer in all the cases consisted of-Fe203,-FeOOH and-FeOOH. The lower rust layer immediately in contact with the metal surface consisted of an asymmetrical doublet due to -FeOOH.     

Mössbauer studies of Ni70Fe10Si8B12 metglass: Reentrant properties

Amorphous metal Fe₁₀Ni₇₀Si₈B₁₂ has been studied by Mössbauer spectroscopy without and with an weak applied field in the plane of ribbons. Reentrant properties have been confirmed with the existence of a canted state at low temperature. Studies with different values of the applied field have shown that a field near 50 0e is sufficient to saturate the average direction of the ferromagnetism.     

FRW-Cosmological Model for Conharmonically Flat Space Time

This paper deals with FRW-Cosmological model of the universe for conharmonically flat space time. Einstein field equations with variable cosmological term are solved by using a law of variation for Hubble’s parameter, which is related to average scale factor. A new class of exact solution of the field equation has been obtained in which cosmological-term decreases with cosmic time. A detailed study of physical and kinematical properties of the model is also carried out.