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Positive and negative interaction have been found to co-exist in Sm2Fe17Nx and Nd2Fe14B isotropic magnets. The measured positive interaction may come from the interactions from those grains with small deviation angle between its easy axis and the direction of external field, whereas the negative interaction may come from those grains with large deviation angle. The numerical calculations of the magnetostatic fields around a particle indicate that the positive interaction results from the magnetostatic interaction among nearest-particles located in forefront and backfront along their common easy axis of magnetizations and the negative interaction results from the magnetostatic interaction among those particles located in same plane perpendicular to their easy axis of magnetizations. In soft-hard multiphase materials, larger the remanence enhancement is, stronger the negative interparticle interaction becomes. The remanence enhancement in SmFeN materials have also been investigated.

In this work, the crystalline environment of DyTiFe1 1-xCox is studied by 57Fe Mossbauer spectroscopy. Results indicate that Co prefers to occupy 8f site and Ti prefers 8i site. For rare earth- transition based compounds, we suggest one experimental rule which gives a general description on the tendency of the preferential occupation of the transition elements on transition type crystalline sites in such compounds: Transition atom with smaller atomic number or with smaller number of d electrons has a preferential tendency to occupy the site with larger transition-transition distance; meanwhile the transition atom with the large atomic number prefers to occupy the transition sites with relative short transition-transition distance. Besides it seems that we can treat Al like a quisi-transition at atom with the atomic number smaller than that of Cr when Al participates in substitution in rare earth - transition based compounds.

In the present work, the structure, magnetic properties and magnetoresistance effect of Ni1−xMnxFe2O4 (x=0,0.2,0.4,0.8) sintered ferrites are studied. Results indicate that these ferrites crystallize in the cubic spinel structure. Curie temperature decreases but the saturation magnetization increases with increasing Mn content in Ni1−xMnxFe2O4 sintered ferrites. A large magnetoresistance effect has been found in samples x=0.4 and x=0.8.

In the present work, the magnetoimpedance effects in the amorphous (Co0.85Fe0.06Cr0.02Ni0.07)75Si10B15 ribbon has been investigated. Results show that three frequency dependencies of the change ratios of magnetoimpedance, magnetoresistance and magnetoreactance intersect at a certain frequency where the change ratio of magnetoimpedance phase is zero.

FeSiO 2 fine particle assembly, prepared by high-energy ball milling, exhibits coercivity which is enhanced by two orders of magnitude with respect to the α-iron. With increasing the fraction of x v from 0.3 to 0.6, the coercivity of Fe x (SiO 2 ) 1−x decreases from 350 Oe to 50 Oe. The coercivity of milled Fe 0.3 (SiO 2 ) 0.7 first increases, undergoes a peak and then decreases, with increase in the deviation angle between the direction of external field and the aligned direction of the magnetically aligned powder-bonded samples. The magnetic reversal of FeSiO 2 fine particles assembly can be explained by incoherent rotation for small values of deviation angles, and by coherent rotation for large values of small deviation angles.

In the present work we suggest a method to calculate the crystalline anisotropy constants from a hardmagnetic material with polycrystalline structure taking account of effects of the misalignment of grains and effective total demagnetization factor.

In the present work, the sign of the magnetostatic interaction in ferromagnet is discussed. A simple model is suggested to explain the remanence enhancement in isotropic hardmagnetic materials.

In this paper, Nd 2 Fe 23 B 3 , Dy 2 Fe 23 B 3 amorphous ribbons have been prepared by melt spinning method. The thermostability for the Nd 2 Fe 23 B 3 phase was investigated. The hardmagnetic properties of the Nd-Fe-B ribbon after annealing at 900°C can be attributed to the Nd 2 Fe 14 B phase coming from the dissolution of the Nd 2 Fe 23 B 3 cubic phase. For the Dy 2 Fe 23 B 3 ribbon, the magnetization of the amorphous increases more quickly than that of the crystallized cubic phase. The interaction of Dy-Fe is antiferromagnetic. The Mossbauer study for the Dy 2 Fe 23 B 3 cubic phase at the room temperature has been investigated. We also attempt to find the phase relationship in rare earth(R)-transition(T)-boron(B) ternary systems. The R( 1,2 )−T( 7m+2n )− n+1 relation form is suggested.

In the present work, the diffusion mechanism of gas atom (C, N) into Sm2Fe17 lattice has been investigated. Results indicate that gas atoms (C, N) under different states of gas absorption content x in Sm(2)Fe(17)Z(x) (Z=C, N) are of different diffusive activity due to the interaction strength between gas atom and interstitial site of Sm2Fe17 molecule. In the region of x x(0), such interaction is small and part of nitrogen atom with amount of Delta x=x-x(0), in Sm(2)Fe(17)Z(x) are active for further diffusion and can migrate easily in Sm2Fe17 lattice.

The infrared and Raman spectra of α-Si:H:Cl films prepared by glow discharge were measured. The dependence of SiCl bonds on the preparation conditions of films was investigated. The results show that chlorine is incorporated only in monochloride bonding geometry at higher substrated temperature (400 C). And SiCl2 bonds were also formed at lower substrate temperature (200–300 C). The band at 795 cm−1 is related to the incorporation of oxygen and hydrogen rather than that of chlorine.

The structure and magnetocrystalline anisotropy of SmMo2Fe10 alloy were investigated. X-ray analysis revealed that SmMo2Fe10 has the tetragonal ThMn12 structure with parameters a = 8.6015 A , c = 4.7996 A , v = 355 A 3 . SmMo2Fe10 has an easy axis [001] from 78 to 293 k. The temperature dependence of the magnetization was measured. The Curie temperature was found to be 463 K. The temperature dependence of magnetic anisotropy field in the range 77 k – 300 k was determined. The value of magnetic anisotropy field at 300k is 45 kOe. It shows that SmMo2Fe10 based alloys can serve as permanent magnet materials.

All of GaAs-like and AlAs-like LO confined modes in (GaAs)n(AlAs)n short period superlattices are reported, to acknowledge, for the first time at room temperature and off-resonance conditions. It is shown that the Raman activity of confined LO modes is dependent on the scattering configuration. For the orientation x = (110), y = (110) and z = (001), the complete modes of confined LO phonons are observed in z(xx)z configuration, and no modes in z(xy)z configuration.